Background & objectives:Adrenal insufficiency (AI) is rarely diagnosed in patients with HIV infection, in spite of autopsy studies showing very high rates of adrenal involvement. This study was aimed to determine the presence, patterns and predictors of AI in patients with HIV infection.Methods:Consecutive HIV patients, 18-70 yr age, without any severe co-morbid state, having at least one-year follow up at the antiretroviral therapy clinic, underwent clinical assessment and hormone assays.Results:From initially screened 527 patients, 359 patients having good immune function were analyzed. Basal morning cortisol <6 μg/dl (<165 nmol/l; Group 1), 6-11 μg/dl (165-300 nmol/l; Group 2), 11-18 μg/dl (300-500 nmol/l; Group 3) and ≥18 μg/dl (500 nmol/l; Group 4) were observed in 13, 71, 199 and 76 patients, respectively. Adrenocorticotropic hormone (ACTH) stimulation test revealed 87 patients (24.23%) to have AI. AI in groups 1-4 was 100, 56.34, 17.09 and 0 per cent, respectively. AI patients were more likely to be females (P< 0.05), having longer disease duration (P< 0.05), immune reconstitution inflammatory syndrome, hyperkalaemia (P< 0.01), lower fasting glucose (P< 0.01), dehydroepiandrosterone sulphate (DHEAS) and vitamin D. Regression analysis revealed morning cortisol and DHEAS to be best predictors of AI (P=0.004 and 0.028, respectively).Interpretation & conclusions:AI is a significant problem in HIV-infected individuals, observed in nearly a quarter of patients. Diagnosis warrants high index of suspicion and low threshold for screening, especially in those having low DHEAS and hyperkalaemia. Morning cortisol is a reasonable screening test, with ACTH stimulation warranted to confirm diagnosis, especially in patients with morning cortisol <11 μg/dl (300 nmol/l).