Objective: Most smoking cessation studies have used long-term abstinence as their primary outcome measure. Recent research has suggested that long-term abstinence may be an insensitive index of important smoking cessation mechanisms. The goal of the current study was to examine the effects of 5 smoking cessation pharmacotherapies using Shiffman et al.'s (2006) approach of examining the effect of smoking cessation medications on 3 process markers of cessation or smoking cessation milestones: initial abstinence, lapse, and the lapse-relapse transition. Method: The current study (N = 1,504; 58.2% female and 41.8% male; 83.9% Caucasian, 13.6% African American, 2.5% other races) examined the effect of 5 smoking cessation pharmacotherapy treatments versus placebo (bupropion, nicotine lozenge, nicotine patch, bupropion + lozenge, patch + lozenge) on Shiffman et al.'s smoking cessation milestones over 8 weeks following a quit attempt. Results: Results show that all 5 medication conditions decreased rates of failure to achieve initial abstinence and most (with the exception of the nicotine lozenge) decreased lapse risk; however, only the nicotine patch and bupropion + lozenge conditions affected the lapse-relapse transition. Conclusions: These findings demonstrate that medications are effective at aiding initial abstinence and decreasing lapse risk but that they generally do not decrease relapse risk following a lapse. The analysis of cessation milestones sheds light on important impediments to long-term smoking abstinence, suggests potential mechanisms of action of smoking cessation pharmacotherapies, and identifies targets for future treatment development. (Contains 3 figures, 3 footnotes and 2 tables.)