The Cauayan City National High School was established on June 3, 1997 as high school extension of Cauayan Polytechnic College with an initial enrolment of 1,065 and a teaching force that comprised five regular teachers, four Local School Board teachers and ten PTCA      –paid teachers. The LGU-owned Ladies’ Dormitory located at Burgos St. in Barangay District I served as the first campus where 18 freshmen sections were housed.

         The school was established through the concerted efforts of the administration of Cauayan Polytechnic College, now Isabela State University, Cauayan Campus, the Local Government Unit of Cauayan, then a first-class municipality, and the Parent Teachers and Community Association(PTCA) to cushion the impact of Commission on Higher Education (CHED) Order number 3, series of 1996 mandating the gradual phase down of secondary programs to a maximum of 500 students and limiting the number of freshmen entrants to 125.

         The following school year registered an 108% increase of enrolment  students that prompted the school administration to put up satellite classes in the different barangays to accommodate all enrolees. Two satellite classes were organized in each of the following barangays: Buena Suerte, Dabburab and District I. On the other hand, eight satellite classes were formed in Minante I.

         The school year 1998-1999 registered a record high enrolment of 3,878 students that necessitated the implementation of two-shift scheme. Students who came from outer most barangays and nearby municipalities took the morning session (7:30-12:30), while students who came from the poblacion took the afternoon session (1:00-6:00). It was also during this time when the school acquired a three-hectare lot in barangay Turayong, the present location of the school. The first school building was erected during this period- the Heherson Alvarez building which now serves as the administration building of the school.

         On July 19, 1999, the school achieved its autonomy from its mother school and was named CAUAYAN NATIONAL HIGH SCHOOL by virtue of a Department Order. In January 2000, the school was included in the General Appropriations Act (GAA) with an initial yearly MOOE of Php 55,000.

         It was also during this year when the first three regular teaching items were given to the school. Since then, more buildings were erected yearly to accommodate over 4,000 students in the new campus. More teacher items were also given to the school to address teacher shortage. Sillawit Extension was also established during the School Year 2000-2001 with an initial enrolment of 300 students. The school serves four barangays, namely: Sillawit, Nungnungan II, Alinam and San Isidro. After five years of operation, CNHS Sillawit Extension was separated from CNHS and it became Sillawit National High School.

         This development diminished the yearly enrolment to over 3,478 students in the succeeding year. In December 2008, CCNHS Research Extension located at Minante I, Cauayan City was established with two sections in the First Year Curriculum. Students came from the following feeder barangays, namely: San Francisco, Faustino, Minante I and II.

         January 4, 2010 ushered a brighter prospect for CCNHS because a new school head took the leadership helm, Mr. John R. Mina. He is not new to the school since he was one of the pioneer teachers of the school. He rose from the ranks- classroom teacher for six years (1997-2003), Head Teacher III for four years, and Principal I for three years.

         The new school head who finished his Masters degree at the College of Education of the University of the Philippines Diliman as a NEAP scholar instituted many reforms in the school that ushered in a culture of excellence. His term is indubitably the crowning glory or golden age of the school, so to speak because of the numerous feats and achievements of the school, most notable of which are three national awards- Brigada Eskwela Best Implementer-Big School Category in 2010, 2011 and 2012, Hall of Fame Award in Brigada Eskwela, and Grand Champion in the Nationwide Search for Best School Forest Park. The school received a total of 1.2 -million pesos as cash prize for the latter.

         Moreover, the school etched a lasting legacy in various academic, co and extra-curricular competitions from division to international levels. The school has become a benchmark of schools in Region 02 with the outstanding feats of students, teachers and the school head by reaping awards and recognitions in the different disciplines.

         In due time, two extension schools were established to decongest the main campus. Cabaruan Extension was established in June 2010 while Marabulig Extension started its operation in June 2013 through proper representations made by the school head. These two schools have separate budgetary allocations from the General Appropriations Act a year after they were established. This made the two schools managed their own resources that prompted their continuous development. These schools were managed by former teachers of the school who passed the National Qualifying Examinations of School Heads. At least five of them are now deployed in various public secondary schools in SDO Cauayan City. Their managerial skills were honed when

         As development happened from time to time, deeper harmonious rapport between and among teachers, parents and students and community folks had been established. Many more are expected to be constructed in the institution these coming years with the inclusion of the full implementation of the Senior High School Program.

         All these and more are done through collaboration and concerted efforts of all the stakeholders through the leadership of the school head.

         The construction of academic nooks, library extension stakeholders’ gymnasium, concrete fence, comfort rooms and learning resource centers by department, acquisition of school bus, construction of the TLE Food Laboratory, Speech Laboratory, 2-CL Computer Laboratory and 5 CL buildings, perimeter fence, guard house, covered pathway, ground gravelling , levelling and concreting to name a few had greatly advanced the status of both teachers and students to a higher pedestal. The school has been recognized region wide and even nationwide with its great academic achievement having produced students and teachers excelling in various fields.

         The school at present offers five curricula, namely, Science, Technology & Engineering (STE), Special Program in the Arts (SPA) Curriculum , K-12 Enhanced- Basic Education Curriculum , Special Program in Sports(SPS) and Special Education(SPED).

         Meanwhile, success has been achieved in various academic and skills competition. These added laurels bagged by this pillar of excellence.