OBJECTIVE:Parenting programs are the recommended strategy for the prevention and treatment of disruptive child behavior. Similar to most psychosocial interventions, it is unknown which components of parenting programs (ie, parenting techniques taught) actually contribute to program effects. Identifying what parents need to be taught to reduce disruptive child behavior can optimize intervention strategies, and refine theories on how parenting shapes disruptive child behavior. METHOD:In two meta-analyses, we updated the evidence-base for effectiveness of parenting programs delivered at various levels of prevention and treatment of disruptive behavior. We searched six databases (eg, PsycINFO, MEDLINE) for randomized trials and coded the parenting techniques taught in each program. We identified the techniques associated with program effects in general, and for prevention versus treatment, and immediate versus longer-term effects, specifically. RESULTS:Parenting program effects on disruptive behavior gradually increased per level of prevention (universal d = -0.21, selective d = -0.27, indicated d = -0.55) and treatment (d = -0.69) (Meta-Analysis 1: 154 trials, 398 effect sizes). Three of 26 parenting techniques were associated with stronger program effects: positive reinforcement, praise in particular, and natural/logical consequences. Several additional techniques (eg, relationship building and parental self-management) were associated with stronger effects in treatment but weaker effects in prevention. No techniques were associated with stronger longer-term effects (Meta-Analysis 2: 42 trials, 157 effect sizes). CONCLUSION:Positive reinforcement and nonviolent discipline techniques (eg, applying natural/logical consequences) seem to be key parenting program techniques to reduce disruptive child behavior. Additional techniques (eg, parental self-management skills) might improve program effects in treatment, but not in prevention.