There is increasing concern about the number of preschool children displaying problem behaviour. This study examines the relative contribution of potential risk factors, particularly those related to families, to problem behaviour in the lives of a sample of western Sydney three- to five-year-old children. Problem behaviour was assessed using the Child Behavior Checklist (Achenbach & Edelbrock, 1991), encompassing measures of anxious, depressed, uncommunicative, obsessive, somatic complaint, social withdrawal, hyperactive, aggressive, and delinquent behaviours. Particularly salient risk factors associated with problem behaviour were found to be children's behaviour when very young (an indicant of temperament), personal stress in parents associated with concerns about the family and economic worries, and parenting characterised by guilt and anxiety.