A cross-sectional study using a self-administered questionnaire was carried out to determine the prevalence of khat chewing among secondary school students in Agaro, southwestern Ethiopia in 1991. Two-hundred-forty-eight students randomly selected from grade 9 to 12 were included in the study with current prevalence of 64.9%. Khat chewing was found to be associated with being Muslim and male. The most frequent users were also in the age group of 15 to 22 years. The association between khat chewing and grade attended was statistically significant. The health and socioeconomic problems associated with the use of khat are discussed and possible interventions suggested.