This study presents the main clinical findings on 200 AIDS patients at Kilimanjaro Christian Medical Centre in the northern zone of Tanzania, with detailed neurological findings on 135 out of 200 cases and 53 controls. Results show that 21 out of 200 (10.5%) had an obvious focal neurological disorder, including cranial nerve palsies, hemiparesis and paraparesis. Ninety-seven out of 135 (72%) had less obviously detectable neurological disorders, versus 36% of controls (P less than 0.005). Most frequent were AIDS dementia complex (54%), retinopathy (23%), areflexia (21%), pyramidal tract signs (19%) and tremor and incoordination (19%). Frontal lobe release signs (FLRS) were found in 103 out of 135 (76%) patients, versus 36% of controls (P less than 0.005). Advanced and terminal AIDS cases were more likely to have neurological disorders than early AIDS patients. A further study on 87 non-AIDS patients with acute unexplained neurological disorders showed 10 out of 87 to be HIV seropositive. Three case studies are presented. This study suggests that neurological disorders are among the main clinical features of AIDS and HIV disease in Africa.