Background: Studies of childhood obesity have shown that fostering healthy life behaviors is more important than losing weight. However, studies reporting this result did not use a theoretical nursing model, which offers a systematic approach and scientific basis for studying the concepts and principles of nursing practice. Purpose: The aim of this study was to determine the effects of an intervention that is based on Nola J. Pender’s Health Promotion Model (HPM) on the healthy life behaviors and self-confidence of obese children. Methods: This quasi-experimental study enrolled 86 obese children and their parents (48 in the experimental group and 38 in the control group) as participants. The data collection tool was composed of an adaptation of a Pender’s modelbased evaluation form and the BPiersYHarris Self Confidence Scale.[ The experimental group received HPM-based individual and group education, whereas the control group received routine follow-up only. Whereas qualitative data were analyzed using content analysis, quantitative data were analyzed using a paired t test and MannYWhitney U or Wilcoxon test. Results: At the end of the education and follow-up program, experimental group participants showed a significant increase in healthy eating habits such as noting food portions (Z = 5.231, p G .001) and choosing water instead of sugary drinks (Z = 4.130, p G .001) and spent significantly less time per day in front of a television or computer (Z = 5.085, p G .001). Furthermore, after the intervention, experimental group participants had reduced their total body mass index standard deviation score (Z = 6.031, p G .001) and had an average selfconfidence score that differed significantly from the control group (Z = 3.796, p G .001) and that was significantly higher than the average preintervention score (Z = 5.971, p G .01). Conclusions: Health professionals must recognize the physical, psychological, and social risks of obesity in children and focus on these problems to identify appropriate solutions. It is recommended that education and nursing follow-up programs be developed based on nursing models. This study found that patient education based on Pender’s HPM increased healthy life behaviors (e.g., healthy nutrition and increased exercise time) and decreased sedentary activity substantially in the experimental group. This study further suggests that, although Pender’s HPM has not been tested on obese children, this model offers effective guidelines for nursing activities that are targeted on developing healthy life behaviors in children.