The link that has been found between parental use of physical punishment and increased risk of child physical abuse has led public health professionals to target physical punishment as part of their child abuse prevention strategies. However, current programs are limited in their effectiveness because the major reasons for its use are unclear. The purpose of this study was to examine the roles of cognition and affect in maternal use of physical punishment. A social information processing model was used to identify distal (pre-existing) and proximal (situational) maternal predictors. A random sample of 110 mothers of 3-year old children were interviewed regarding two disciplinary situations that occurred during the previous two-week period: one which resulted in the use of physical punishment and one which did not. Logistic regression analysis was conducted to assess the relative individual contributions of both distal and proximal predictors of physical punishment use. The distal variable of maternal attitude toward physical punishment and the proximal maternal variables of perceived seriousness and intent of the child misbehaviour and anger in response to the child misbehaviour predicted physical punishment use. Logistic regression analysis was conducted on a modified social information processing model that included both cognitive and affective predictors of physical punishment use. This model explained 53% of the variance in physical punishment use. The identification of these key components of the decision making process in disciplinary situations can be utilized to establish priorities in educational prog amming aimed at decreasing the rates of parental use of physical punishment and child physical abuse.