ABSTRACT. A longitudinal study was conducted on the psychological well-being of 81 young children (mean age = 8.8 years) living with mothers with AIDS or HIV-infected mothers with symptomatic disease. The relationship between mothers' physical health and children's psychological well-being was investigated. The children were assessed at seven time points over approximately 6 years. Individual growth models were estimated for children's depression, anxiety, and aggressiveness in relation to: mothers' viral load (medical records) and physical functioning, number of HIV-related physical symptoms, and medical visits due to illness (self-report). Results showed significant linear declines in children's depression, anxiety, and aggressiveness over time. Lower levels of physical functioning and more physical symptoms among mothers were associated with higher levels of children's depression, anxiety, and aggressiveness at baseline. Lower levels of physical functioning and more physical symptoms among mothers were associated with initially high but more rapidly decreasing levels of depression among children. However, mothers who began the study in better health appear to have changed in health more quickly than mothers who began the study in poorer health. Thus, stability in mothers' health appears to be associated with a more rapid improvement in children's mental health over time. Our findings suggest that the measures representing observable levels of, and changes in, mothers' health that are most likely to be directly experienced by themselves and their children are the measures that are most predictive of changes in children's mental health over time.