HLA-B27 is a class I surface antigen encoded by B locus in the Major Histocompatibility Complex (MHC) on the short (p) arm of chromosome no.6,presents microbial antigen to T cells. HLA B is a human gene that provides instruction for making a protein that plays a critical role in immune system.HLA-B27 is strongly associated with a certain set of autoimmune disease referred as the ?Seronegative Spondyloarthropathies?, a group of disorders that include Ankylosing Spondylitis (AS) and other inflammatory joint diseases. It has been found that 90% of patients with this rheumatic disease have HLA- B27 antigen , compared with 10% of healthy controls. PCR for detection of HLA-B27 is extremely accurate and considered the standard method. The aim of this prospective study was to identify the positivity rate of HLA-B27 in different age group and sex of patients by using Sequence Specific Primer typing (SSP)-PCR approach in a selected population, suffering from Ankylosing spondylitis. Out of 40 samples,the positivity rate was maximum in age group of above 50 and also analyzed that males are more susceptible to this disease as compared to females.