Background. Teenage smokers cite health concerns as their primary motivators for tobacco smoking cessation. Smoke exposure aggravates the clinical course of asthma, yet few reports have examined the association between asthma and smoking topography and trajectory. Methods. Before their enrollment in a smoking cessation trial, we assessed the smoking topography (i.e., puff volume, maximum puff velocity, puff duration, and interpuff interval) and smoking trajectory (i.e., age of first cigarette, age of daily smoking, time to treatment request, and prior quit attempts) in 30 self-reported asthmatic and 92 nonasthmatic tobacco-dependent teenagers (mean age, 15.2 ± 1.3 years, 28.7% African-American). Approximately one-half of asthmatics used prescribed medications for their asthma. Results. There was no significant difference in smoking topography or smoking trajectory variables between asthmatic and nonasthmatic adolescents, nor between medicated and nonmedicated asthma subgroups. Conclusions. Although tobacco smoking exacerbates asthmatic symptoms, these data suggest that age of smoking initiation, as well as smoking topography characteristics in asthmatic adolescents, does not differ from those of adolescents without asthma. These findings highlight the need for more effective health counseling of asthmatic youth regarding the physical and behavioral effects of smoking.