This study aimed at exploring the impacts of a school-wide no smoking strategy and a classroom-based smoking prevention curriculum on smoking-related knowledge, attitude, behavior, and skill of junior high school students.Using a pre–post quasi-experimental design, 469 seventh-to ninth-grade students at four junior high schools in Taiwan, were selected and separated into three groups according to class unit. Experimental group A experienced a school-wide no smoking strategy and a six-session smoking prevention curriculum. Experimental group B experienced only the school-wide no smoking strategy. The control group experienced no intervention. The students were tested 1 week before intervention began and 1 week after it ended.Experimental group A exhibited a better understanding than either experimental group B or the control group of the dangers of smoking and of techniques for refusing cigarettes; and in fact, group A indicated low smoking intention than experimental group B. Experimental group A also had a better attitudes towards resisting smoking than the control group. However, the intervention had no demonstrable effect on the smoking behavior and on the smoking substitution methods of students.To reduce the smoking rates among junior high school students, diversified school-wide no smoking strategies and standardized, diversified instruments should be adopted so that outcomes of smoking prevention work may be assessed more objectively and effectively.