The aim of this study was to determine whether an intervention from the Triple P Positive Parenting Program system was effective in reducing parental reports of child behavioral difficulties in urban low-income settings in Panama City. A pilot parallel-group randomized controlled trial was carried out. A total of 108 parents of children 3 to 12 years old with some level of parent-rated behavioral difficulties were randomly assigned to a discussion group on "dealing with disobedience" or to a no intervention control. Blinded assessments were carried out prior to the intervention, 2 weeks, 3 months, and 6 months later. Results indicated that parental reports of child behavioral difficulties changed over time and decreased more steeply in the intervention than in the control group. The effects of the intervention on parental reports of behavioral difficulties were moderate at post-intervention and 3-month follow-up, and large at 6-month follow-up. Parents who participated in the discussion group reported fewer behavioral difficulties in their children after the intervention than those in the control condition. They also reported reduced parental stress and less use of dysfunctional parenting practices. There is a limited amount of evidence on the efficacy of parenting interventions in low-resource settings. This pilot trial was carried out using a small convenience sample living in low-income urban communities in Panama City, and therefore, the findings are of reduced generalizability to other settings. However, the methodology employed in this trial represents an example for future work in other low-resource settings.