Alabel National Science High School was established in Alabel, Sarangani Province through RA 8078, authored by the late Congressman James L. Chiongbian. It was conceived in 1995 primarily to cater to the intellectually capable students of Sarangani Province and nearby areas. Classes were formally organized and began on June 3, 1996. Students are intensively screened and mostly belong to the upper 10% of the graduating pupils of the elementary schools in the region.
The school started its operation with zero budget. Funds for the maintenance and operation of the school were sourced out from private individual, GOs, NGOs and LGUs of Alabel, Malapatan and SaranganiProvince. Textbooks, books, chairs and other school needs were provided by nearby high schools and DECS Division Office. Teachers were borrowed from AlabelNationalHigh School and it was manned on a part time basis by the principal of KlingNationalHigh School.
The school received its first budget in CY 1997 with appropriations for salaries of three(3) teacher items and P45,000 allotment for MOOE until finally the school was allotted appropriations for salaries of four (4) teacher items and P1,122,000.00 for MOOE in the 1999 General Appropriation Act.
On June 1, 1999, through DECS Order No. 58 the school was designated as RegionalScienceHigh School for Region XI effective school year 1999 – 2000 in replacement of Philippine Science High School in Mintal, DavaoCity which was previously identified as RSHS for Region XI.
During school year 1999 – 2000, the school has finally occupied its newly constructed building worth P5M erected at 5 hectare school site donated by the benevolent ALCANTARA FAMILY. The school has a water system and school cafeteria with a total budget of P3M. This P8M project was constructed through the CDF of the late Hon. Congressman James L. Chiongbian.
On August 6, 2002, when the SOCSARGEN area was turned over to Region XII the Alabel National Science High School became the Regional Science High School for Region XII.