This study tests Common Sense Parenting (CSP)®, a widely used parent-training program, in its standard form and in a modified form known as CSP Plus, with low-income 8th graders and their families during the high school transition. The six-session CSP program proximally targets parenting and child emotion regulation skills. CSP Plus adds two sessions that include youth, and the eight-session program further targets skills for avoiding negative peers and activities in high school. Over two cohorts, 321 families were enrolled and randomly assigned to either CSP, CSP Plus, or minimal-contact control conditions. To date, pretest and posttest assessments have been completed, with 93 % retention over about a 6-month interval. Here, analyses of preliminary outcomes from pretest to posttest focus on data collected from parents, who represent the primary proximal intervention targets. Intent-to-treat structural equation modeling analyses were conducted. CSP and CSP Plus had statistically significant effects on increased parent-reported child emotion regulation skills. CSP Plus further showed a statistically significant effect on increased parent perceptions of their adolescent being prepared for high school, but only in a model that excluded the CSP condition. Neither program had a significant proximal effect on parenting practices. Emotion regulation, one indicator of self-control, is a robust protective factor against problem behaviors. Intervention effects on this outcome may translate into reduced problems during high school. Moreover, CSP Plus showed some limited signs of added value for preparing families for the high school transition.