Abstract: A prospective cohort study examined the influence of psychosocial factors on the use of general practitioners over a six-month period by 271 children (aged four to nine years) and their mothers. The study was conducted in 10 general practices in the metropolitan area of Perth. The influences of psychosocial factors on use, nonuse and frequency of use by the children were examined, taking into account sociodemographic and morbidity factors. Physical health status, maternal use and financial factors were directly associated with the children's use or nonuse of general practitioners, while maternal stress, a mother's attitude towards her child and the child's psychosocial morbidity were indirectly related. Physical health status, doctor-initiated consultations, maternal stress, children's ages and birth order were directly associated with the children's frequency of use of general practitioners. Depression and anxiety in the mothers, measured with standardised instruments, were not associated with use by the children nor was a mother's level of social support. The results point to the importance of family relationships and illness behaviour in the family when considering use of general practitioners and the importance of using standardised measuring instruments and multivariate designs when studying such complex behaviours as the use of health care.