In 20^th century HIV (Human Immunodeficiency Virus) is the most emerging infection and this infection leading to Acquired Immunodeficiency Syndrome (AIDS) which cause immunosuppersion in patients living with HIV/AIDS (PLWHA) and making these people susceptible to various opportunistic infections that infections are responsible for morbidity and mortality. The pattern of Opportunistic infection in people living with HIV/AIDS attending ICTC Tertiary care hospital, Bikaner was studied. Detailed history taking, clinical examination and laboratory tests were carried out in 100 patients, Male-65 (65%) and Female 35 (35%). tuberculosis was most common frequent opportunistic infections in HIV patients accounting for 59% of all opportunistic infections, followed by candidiasis in 41% of all patients. Pneumocystosis was seen in 11%, Cryptococcal infection in 10% and parasitic diarrhoea in 17%. Finding points to be importance of early diagnosis and treatment of opportunistic infections in order to improve quality and expectations of life.