The present study involved an examination of the extent to which a wide range of child, parent, family, and program-related factors predicted child behavior and parenting outcomes after participation in an 8-session online version of the Triple P-Positive Parenting Program. Participants were mothers and fathers of 97 children aged between 3 and 8 years displaying elevated levels of disruptive behavior problems. For both mothers and fathers, poorer child behavior outcomes at postintervention were predicted by the number of sessions of the intervention completed by the family. For mothers, postintervention child behavior was also predicted by the quality of the mother-child relationship at baseline; for fathers, baseline child behavior severity was an additional predictor. Mothers' postintervention ineffective parenting was predicted by session completion and preintervention levels of ineffective parenting, whereas the only predictor of fathers' ineffective parenting at postintervention was preintervention levels of ineffective parenting. Socioeconomic risk, parental adjustment, and father participation in the intervention were not significant predictors of mother- or father-reported treatment outcomes. The implications of the findings for the provision of online parenting support are discussed.