BackgroundSupporting smoking cessation at pharmacies can be challenging owing to difficulties in recruiting smokers to participate in cessation programs, insufficient communication skills among pharmacists, and lack of knowledge and self-efficacy in successfully quitting smoking in Japan.ObjectiveThis study evaluates the effectiveness of a smoking cessation training program on community pharmacists' knowledge, attitude, and self-efficacy in supporting smoking cessation.MethodsThe study, conducted in Japanese pharmacies with 100 community pharmacists, employed a quasi-experimental design. Two online training programs were implemented. Participants completed a web-based survey assessing their knowledge, attitude, and self-efficacy in supporting smoking cessation before, immediately after, and 1 year after the training program. A two-way analysis of variance with a mixed model was used to examine score changes at each time point.ResultsTotal knowledge scores significantly increased between baseline and immediately after training and baseline and 1 year after training. The total attitude scores between baseline and immediately after training differed significantly. However, no differences were noted between baseline and 1 year after training. Total self-efficacy scores significantly increased at baseline, immediately after training, and between baseline and 1 year after training. Despite no significant interactions between the programs, there was a partial interaction effect on knowledge, with only the customized program having items whose knowledge levels improved after 1 year.Conclusion and RelevanceThe training program improved community pharmacists' knowledge, attitude, and self-efficacy regarding smoking cessation support. The customized program must be reinforced to improve support performance and maintain attitude.