The onset of smoking behavior in adolescents has been described as a process, beginning when children are young. Little empirical evidence is available, however, on the nature and specifics of the onset process in young children. More information is needed about the early stages of smoking onset in order to design interventions for young children and for early triers. The purpose of the present study was to describe several onset-related variables in young girls and boys and to discuss implications for designing prevention interventions that target young children. A total of 1,663 5th-grade students completed a questionnaire assessing smoking behavior, psychosocial characteristics, and perceptions of a "smoker" image. Saliva samples for cotinine analysis were also collected. Students were classified as either never-triers (never tried a cigarette) or early triers (tried one or more cigarettes) on the basis of self-reported smoking. Most students who had tried a cigarette were in the early stages of smoking onset, because approximately 30% had tried one cigarette and less than 10% had tried a second. Triers versus never-triers differed on their reported images of smokers, and several psychosocial characteristics predicted trying a cigarette and intentions to smoke for boys.