This study examines the role of implementation dosage in the effectiveness of a school-based social and emotional skills building curriculum, The Talking with TJ video series, among urban, predominantly minority elementary school children. It was hypothesized that children in higher dosage schools will exhibit greater improvements in their social skills and reductions in their problematic behaviors than children from low dosage schools. It was also expected that children in higher dosage schools will report more positive feelings about their self-concept. Results from 655 second and third graders from 6 elementary schools in an urban district confirmed the first hypothesis. After controlling for pre-assessment differences between the two dosage groups, ANCOVAs confirmed that children in high implementation groups had higher ratings of social skills and lower ratings of problem behaviors during post-assessment period while their counterparts received higher ratings of problem behaviors and lower ratings of social competence. Findings indicate differential effects on social skills and problem behaviors. There were no significant differences in students' self-concept between the two dosage groups. It was concluded that subsequent research on school-based social competence programs should incorporate implementation fidelity measures, such as implementation dosage in assessing a program's effectiveness.