While the effect of mothers' mental health on children's development is well documented, studies of the predictive value of prenatal psychological distress in fathers for their children's early psychosocial and behavioural development are still scarce. The overall aim of this project was to investigate if and to what extent expectant fathers' mental health presents a risk factor for their children's development. This study was based on data from 31,663 children participating in the Norwegian Mother and Child Cohort Study (MoBa) (Magnus et al., 2006). Data on fathers' and mothers' prenatal psychological distress were obtained through the self-report at week 17 or 18 of gestation. Information on children's social, emotional and behavioural development at age 3 years was obtained from mothers' reports. Three percent of fathers had high level of psychological distress. We found a small, but consistent association between fathers' psychological distress and children's behavioural difficulties, emotional difficulties, and social functioning. The associations did not change after adjusting for fathers' age, education, marital status, somatic conditions, physical activity, and mothers.