The College of Arts and Sciences (CAS) is the service college of the Mariano Marcos State University (MMSU). It was created soon after the University was established in 1978 to accomplish the institutional goal of providing quality liberal education to students, in addition to satisfying the need to offer degree programs in the arts and sciences.

The college started with 45 faculty members distributed among eight departments, each headed by a chairman. As the student and faculty population increased, the college started offering degree programs and the departments became specialized. At present, the college has nine departments, namely: Biological Sciences, Environmental Science, Physical Sciences, Languages, Literature and Communication, Mathematics, Computer sciences, Physical education and Social sciences.

The college is headed by a dean assisted by a college secretary.