An analysis of the Global Youth Tobacco Survey for Kilimanjaro, Tanzania was carried out to assess sex differences in the prevalence rates and predictors of current cigarette smoking among in-school adolescents. A total of 2323 adolescents participated in the study of whom 53% were females and 47% males. The prevalence of current cigarette smoking was 3.0% and 1.4% among males and females, respectively. The common factors that were significantly positively associated with cigarette smoking between sexes were: having more pocket money, closest friend smoked cigarettes, seeing actors smoke on TV, videos or movies, and seeing advertisements for cigarettes at social gatherings. Seeing anti-smoking messages at social gatherings were negatively associated with smoking among both sexes. While having had something such as a t-shirt or pen with a cigarette brand logo on it was positively associated with cigarette smoking among males, it was negatively associated with cigarette smoking among females. Male adolescents older than 15 years, those in their 9th year of schooling, and those who had seen cigarette brand names on TV were more likely to smoke. Meanwhile, male respondents who were in their 8th year of schooling, had seen anti-smoking media messages, and advertisements for cigarettes in newspapers or magazines were less likely to smoke. Among female adolescents, those who had parents who smoked, and surprisingly those who perceived that cigarette smoking as harmful were more likely to smoke. Interestingly, seeing advertisement for cigarettes on billboards was negatively associated with smoking among female adolescents. Interventions aimed to reduce adolescent smoking need to be designed and implemented with due consideration of sex differences in these associated factors.