The present investigation examined intrinsic and extrinsic reasons for quitting among daily cigarette smokers with posttraumatic stress disorder (PTSD) as compared to clinical daily smokers with other anxiety and mood disorders (AM) and daily smokers with no current Axis I psychopathology (C) prior to a self-guided quit attempt. It was hypothesized that (1) the PTSD group would report greater intrinsic (ie, self-control and health concerns) reasons for quitting smoking, and (2) among those with PTSD, anxiety sensitivity (fear of anxiety; AS) would predict greater intrinsic reasons for quitting smoking. Participants were 143 (58.7% female; M(age) = 29.66 years, SD = 11.88) daily cigarette smokers. Partially consistent with prediction, the PTSD group reported significantly greater self-control intrinsic reasons for quitting, but not health concern intrinsic reasons, than the C group (p < .01). The PTSD group also reported greater immediate reinforcement extrinsic reasons for quitting than the C group (p < .05). The PTSD and AM groups did not significantly differ on any reasons for quitting. Also partially consistent with hypotheses, higher levels of anxiety sensitivity in daily smokers with Axis I psychopathology (both PTSD and AM groups) significantly predicted greater self-control intrinsic reasons for quitting. AS did not significantly predict immediate reinforcement extrinsic reasons for quitting. The current findings suggest that individuals with PTSD and other psychopathology may have unique motivations for quitting smoking that could be usefully explored within smoking cessation treatment programs.