Infection with Mycobacterium avium intracellulaire (MAI) is an increasingly important problem in patients infected with Human Immunodeficiency Virus (HIV). The objective of this study was to identify whether specific patterns of accumulation of Ga-67 citrate occur in HIV antibody positive patients with disseminated MAI infection. A retrospective review of Ga-67 scinigraphy was performed in 18 HIV antibody positive patients with MAI and 20 HIV antibody positive patients without MAI (who acted as a control group). A wide range of abnormalities was seen in both groups of patients and no single abnormality was diagnostic of MAI. However MAI was likely (sensitivity 89%, specificity 70%) in the presence of two or more of the following; accumulation of Ga-67 in lymph nodes, paranasal sinuses or colon or reduced uptake in the bone marrow. No specific abnormality on Ga-67 scintigraphy in HIV antibody positive patients enables a diagnosis of MAI to be made. Subtle and non specific abnormalities of Ga-67 may be the only scintigraphic evidence of active, Mycobacterium avium intracellulare infection. © 1995 The Royal College of Radiologists.