The purpose of this study was to assess the value of including repetition and reinforcement in a dental health education program for school children. Sixty-one pupils, 11 to 13 years of age, were divided into three groups according to room assignments. Group I (control) received no oral hygiene lectures or instructions until the conclusion of the experiment. Group 2 (nonreinforced) received one lecture and a toothbrushing lesson, but no repetition or reinforcement. Group 3 (reinforced) received the same program as Group 2 on the initial visit and also received two additional visits for repetition and reinforcement of the lectures and instructions, plus a final summary lecture. Six visits were conducted at intervals of 0, 1.5, 3, 8, 20 and 52 weeks, following a double-blind experimental format. PHP scores were obtained on all subjects on each of the six visits. It was concluded that the repetition and reinforcement components of this dental health education program were of significant value in improving the oral hygiene performance of the school children over a period of 1 year. The findings provide evidence of the desirability of incorporating these concepts in plaque-control programs.