The Isabela State University was established through the Presidential Decree (P.D.) 1434 by the then President Ferdinand Marcos on June 10, 1978 merging two state colleges – Isabela State College of Agriculture (ISCA) in Echague and Cagayan Valley Institute of Technology in Cabagan. The said decree also transferred the college level programs of Isabela School of Arts and Trades (ISAT) in Ilagan; San Mateo Vocational and Industrial School in San Mateo and Jones Rural School in Jones to the new State University. The merger identified Echague campus as the main campus and administrative site, and mandated the University to establish an effective and efficient institution of higher learning that will provide better professional and technical training in agriculture, the arts, sciences, humanities, and technology and in the conduct of scientific researches and technological studies.

In 1999, the CHED Memo Order no. 18 1999 which provides the guidelines for the integration of CHED institutions to State Universities and Colleges (SUCs) was issued. Pursuant to this order, the first CHED supervised institution, the Cauayan Polytechnic College at Cauayan, Isabela, was integrated to the University. In 2002, two more CHED Supervised Institutions were integrated to the system – the Roxas Memorial Agricultural and Industrial School (RMAIS) in Roxas, Isabela, the Delfin Albano Memorial Institute of Agriculture and Technology (DMIAT) in San Mariano, Isabela and the Angadanan Agro-Industrial College (AAIC) in Angadanan, Isabela. Later, through the collaborative efforts of ISU and the local governments of Palanan and Santiago City, two extension units were added to the system-ISU Palanan and ISU Santiago.

The Isabela State University System is strategically located in the middle of the Cagayan Valley region, which is composed of the island province of Batanes, the valley provinces of Cagayan and Isabela and the generally mountainous provinces of Nueva Vizcaya and Quirino. The province of Isabela is composed of 34 municipalities, 3 cities, and 2,292 barangays. Coincidentally, the ISU satellite campuses are situated along the regions “Midrib-Peripheral Growth Centers and Socio Economic Development Zone” where the major urban and commercial centers of the region are located. Another strategic advantage is the University’s proximity to the site of the Regional Agro-Industrial Center (RIC) of Cauayan City, Isabela and its accessibility to Sta. Ana, Cagayan, and the entry point for international trade, and also Tuguegarao City and Santiago City, the two regional trade, financial and commercial centers of the region.

Forty-one years after its establishment, the University has become a credible Higher Education Institute (HEI), having been awarded by the Association of Accrediting Agencies of Chartered Colleges and Universities of the Philippines (AACCUP) as the SUC with the most number of accredited programs in 2012 as well as one of the few Level IV SUCs in the country. Also, ISU has been named one among 21 leading SUCs in the Philippines. ISU has recently assumed leadership roles in research not only in Region 02, but in the country and in Asia as well. It is now the host or base agency of two regional research centers: the Higher Education Regional Research Center under CHED and the Cagayan Valley Agricultural Resources Research and Development under PCAARRD-DOST. Having been chosen as the base agency is a recognition of ISU’s superiority and dominance among HEIs in the region in terms of capability in research management and scientific undertakings. Presently, ISU is the seat of at least 12 R and D centers and laboratories, proof of its strong R and D capability. With its educational leadership and pioneering roles in research, along with the strategic location of its satellite campuses in the region, the University has been successfully achieving its vision, mission, and goals and objectives. Today, ISU stands as a credible partner of development in the country and with the dedicated commitment of its faculty, support staff, students and the people behind its success, the future will see the University grow to even greater heights.