Abstract Introduction Helping smokers to quit is an important task of general practitioners (GPs). However, achieving tobacco abstinence is difficult, and smokers who fail may still want to improve their health in other ways. Therefore, Swiss GPs developed a multithematic coaching concept that encourages health behavior changes beyond smoking cessation alone. Aims and Methods To compare the effectiveness of such coaching with state-of-the-art smoking cessation counseling, we conducted a pragmatic cluster-randomized two-arm trial with 56 GPs in German-speaking Switzerland and 149 of their cigarette smoking patients. GPs were instructed in either multithematic health coaching or smoking cessation counseling. After 12 months, we compared their patients’ improvements in cigarette consumption, body weight, physical inactivity, alcohol consumption, stress, unhealthy diet, and a health behavior of their own choice, using hierarchical logistic regression models and Fisher’s exact and t tests. Results Over 95% of all participants achieved clinically relevant improvements in at least one health behavior, with no difference between study arms (health coaching vs. smoking cessation counseling: aOR = 1.21, 95% CI = [0.03–50.76]; and aOR = 1.78, 95% CI = [0.51–6.25] after non-responder imputation). Rates of clinically relevant improvements in the individual health behaviors did not differ between study arms either (they were most frequent in physical activity, achieved by 3 out of 4 patients), nor did the extent of the improvements. Conclusions Multithematic health coaching and state-of-the art smoking cessation counseling were found to be comparable interventions, both in terms of smoking cessation success and, quite unexpectedly, their effects on other health behaviors. Implications The findings of our study suggest that in general practice, multithematic health coaching is an effective smoking cessation intervention, and conversely, monothematic smoking cessation counseling also achieves the beneficial effects of a multithematic health behavior intervention. This opens up the possibility for GPs to support their smoking patients in improving their health behavior in additional and more flexible ways.