AimsTo investigate whether or not a stage tailored intervention is more effective than a non-stage tailored intervention of the same intensity in reducing alcohol use among job-seekers with unhealthy alcohol use, and whether initial motivation to change is a moderator of efficacy. DesignA three-group randomized controlled trial with 3-, 6- and 15-month follow-ups. SettingThree job agencies in Germany. ParticipantsA total of 1243 job-seekers with unhealthy alcohol use were randomized to (i) stage tailored intervention based on the transtheoretical model of change (ST), (ii) non-stage tailored intervention based on the theory of planned behaviour (NST) and (iii) assessment only (controls). Participants received feedback letters and manuals at baseline and 3months later. MeasurementsPiecewise latent growth models were calculated measuring change in alcohol use' from baseline to month 3 (active intervention phase) and from months 3 to 15 (post-intervention phase, primary outcome). Motivation to change was included as a 4-point continuous measure. FindingsAll groups reduced alcohol use from months 0 to 3 (controls: mean=-0.866, NST: mean=-0.883, ST: mean=-0.718, Ps0.001). Post-intervention (months 3-15), low-motivated individuals in the ST group showed a greater reduction than those in the control group (=0.135, P=0.039, Cohen's d=0.42) and in the NST group (=0.180, P=0.009, Cohen's d=0.55). In contrast, compared to the ST group (=0.030, P=0.361), alcohol use decreased more strongly with higher initial motivation in the NST group (=-0.118, P=0.010). ConclusionsAmong job-seekers with high levels of alcohol consumption, an intervention tailored to motivational stage of change' was more effective than a non-stage tailored intervention for reducing alcohol use 15 months after baseline assessment in participants with low initial motivation to change.