Longitudinal data were used to investigate direct and indirect effects of demographic factors, parameters of chronic health conditions, service use variables, and perception of family impact of illness on mental health of 169 mothers of children with diverse chronic health conditions. Bivariate analyses indicated that baseline assessments of demographic factors, condition parameters, and service use were: (1) generally unrelated to maternal mental health at 1 year and (2) modestly related to maternal perception of the condition's impact on the family 1 year later. Perceived impact and maternal mental health themselves were moderately related. Multivariate analyses indicated that the need to watch for changes in the child's condition, the presence of communication or speech problems, and the number of hospitalizations in the previous year predicted maternal perceptions of the impact of the condition 1 year later. Mothers perception of impact had a direct effect on mothers' mental health after accounting for condition parameters. Results suggest that condition parameters and service use can affect maternal mental health through mothers' perceptions of the impact of the condition on family life. Implications for interventions to prevent maternal health problems are discussed.