Old Cadets Association of Sylhet (OCAS) was established in Dhaka on 6th august 1982.

Principal of Sylhet Cadet College at that time was the the first President of OCAS. The first Vice President was Md Afaq Ahmad (01/186) and to lead the organization further, Farooque Mohammad (01/02) was selected as first General Secretary (GS).

The first Constitution of OCAS was made in 1982. Later in 2002, after some amendments, the constitution was revised by the elected central OCAS Executive Committee.

The first reunion was held in 1990 at Sylhet Cadet College. The President and GS during the first reunion were Mirza Ashab Baig (01/198) and Md Abdun Naser Khan (04/35) respectively.

OCAS was registered at the Registrar of Joint Stock Companies and Firms on 3rd August 2002.