After-school programs can be implemented by school nurses to facilitate healthy lifestyle choices in children with the goal of decreasing obesity. Kids Living Fit[TM] (KLF), an after-school program designed by community hospital nurses, was implemented in elementary schools and focused on best lifestyle choices regarding foods consumed and activities chosen for children in grades 2 through 5. Study measures included comparison of body mass index (BMI) percentiles for age and gender and waist circumference between two self-selected groups composing a total sample size of 185 participants: the KLF intervention group (n = 80) and the no-intervention/ contrast group (n = 105). The 12-week intervention included a weekly fitness program and monthly dietitian presentations. Participants completed food and activity diaries and wore pedometers. In pairwise comparisons, the KLF group had a significant decrease in BMI percentile between baseline and follow-up (-2.3%) compared with the contrast group. The KLF group also demonstrated a smaller increase in waist circumference than the contrast group. (Contains 5 tables.)