ANHS is located in barangay Anislag, which is situated in the southern part of Albay. It is ten (10) kilometers away from Daraga and it is along the Maharlika Highway to Sorsogon. It caters to the education of the people of Anislag, Villahermosa, Mayon, San Ramon, Talahib, Namantao, Maopi, San Vicente Pequeño, and other adjoining barangays.

In June 1996, the institution was organized with Republic Act No. 6054, known as the Barrio High School Charter, as its legal basis. Thus, Anislag National High School was opened with two full-time secondary school teachers and one part-time elementary school teacher under the administration of the elementary school principal of Anislag Elementary School, Mr. Porferio Llorando, who was also designated as the assistant principal.

Since its creation in 1996, ANHS has operated at the Anislag Elementary School Site. However, due to the increasing population of the school, the Parent-Teacher Association donated for the purchase of a 15, 000 square meter lot opposite the elementary school site in 1982. At present, ANHS has acquired a school site with a total area of 28, 020 square meters.

In the years of existence since 1966, the school administrator, with the strong support of the local government officials, appealed to the higher authorities for the conversion of the barangay high school to a national high school. On June 24, 1983, the request was approved by the Interim Batasang Pambansa. The approval was embodied in the law of RP Blg. 601 entitled “Converting the Municipality High School in the Municipality of Daraga into Anislag National High School.”

In the years 1988 to 1993, an extension school at the población was organized known as Daraga High School. However, in the years 1993-1994, this extension school became independent as it was separated from the administration and supervision of ANHS. In 1994-1995, San Vicente Grande High School at San Vicente Grande, Daraga, Albay, was organized as an extension school of ANHS through the efforts of Mrs. Coreta L. Marollano, the school principal, and Mayor Cicero C. Truinfante, the municipal mayor. In 2003-2004, Bascaran High School was organized as another extension school of ANHS through the efforts of Dr. Richa G. Vibar, school principal, the Bascaran Barangay Council, and Mayor Gerry R. Jaucian, the municipal mayor.

Now, Anislag National High School, with ID No. 301808, is a public secondary school offering Junior High and Senior High School with Academic and TVL tracks as its initial offerings, where HUMSS, GAS, and ABM are the strands for Academic and TVL tracks, with the following strands: Carpentry, HE, AFA, EPAS and CSS as its initial offerings also. 

It has existing academic classrooms occupied by Junior & Senior High School. All of these are standard instructional rooms. However, if we look at the learners-classrooms ratio, ANHS still lacks 31 classrooms as of SY 2018-2019. The Grade 11 classes have an average size of 94, which is the same number as the Grade 12 classes. This number is beyond the recommended learner-classroom ratio. One classroom is utilized as an administration building, one as a Laboratory Room, 4 are used as TVL practical work rooms, and 6 are also utilized as Faculty Rooms, one for EMIS, Registrar and Guidance Office, and one for the Finance Staff. A temporary clinic room is also available. Some classrooms were also utilized as library and computer laboratory rooms, both for JHS & SHS. There are ----- toilets. The learner-toilet Ratio is 117:1 with a lack of 40 toilets for the whole school. The majority of these are used exclusively according to learners' gender.

Currently, it has an enrollment of 3345 students, of which 899 are SHS and 2446 are JHS. It is noticeable that there is a decrease in enrolment of 257 as compared to the last three previous years, when it had an increasing number of enrolments. The decrease in enrolment this year can be attributed to the transfer of learners to other schools offering strands that are not in ANHS and financial-related factors.