To further study the possibility of transmission of HIV infection by close personal but non-sexual, non-parenteral contact we have continued to enroll and evaluate household contacts of adult patients with AIDS. Two hundred and six household contacts of 90 patients with AIDS were evaluated with detailed interviews, physical examinations, and detection of HIV antibodies and p24 antigen from 1984 to 1987; 118 of these contacts were re-evaluated 6-12 months after cessation of household contact or death of the patient. The median duration of household contact from 18 months prior to symptoms in the AIDS patients to last contact was 23 months (range 3-101 months). The median time elapsed from first contact during this period to the last evaluation was 38 months (range 13-66 months). No household contact had signs or symptoms suggesting HIV infection. All 206 were negative for serum antibodies to HIV and HIV p24 antigen, despite extensive sharing of household facilities and items and personal interactions with AIDS patients. This study continues to show that household members without other risks remain at minimal to no risk for HIV transmission (95% confidence interval, 0-1.44) despite prolonged and substantial close non-sexual contact with AIDS patients, and after re-evaluation at a median of 10.9 months after initial evaluation.