Aims/Introduction: Stopping smoking deserves high priority in preventing complications of diabetes; however, only sparse data are available regarding the efficacy of pharmacotherapy in smokers with diabetes. We assessed the efficacy and safety of varenicline in smokers with diabetes who participated in 15 double-blind, randomized, placebo-controlled studies. Materials and Methods: This retrospective pooled analysis included data from smokers of >= 10 cigarettes per day with diabetes. Participants received varenicline 1 mg b.i.d. or placebo for 12 weeks. We examined carbon monoxide-confirmed continuous abstinence rates (CARs) for weeks 9-12, 9-24 and 9-52, and compared safety in participants with and without diabetes. Results: Of 6,771 participants, 323 had diabetes (varenicline n = 162; placebo n = 161). Week 9-12 CAR was higher with varenicline than placebo (43.8% vs 24.8%; odds ratio 2.36, 95% CI 1.47-3.79), as was week 9-24 CAR (27.5% vs 14.4%; odds ratio 2.25, 95% CI 1.27-4.00). Week 9-52 CAR was 18.4% for varenicline and 10.1% for placebo (odds ratio 2.00, 95% CI 0.90-4.49). The most commonly-reported adverse events in participants with diabetes for varenicline vs placebo were: nausea (27.2% vs 8.1%); headache (9.3% vs 9.9%); and insomnia (8.6% vs 5.6%), incidences that were similar in participants without diabetes (29.6% vs 9.7%; 13.4% vs 10.9%; and 11.4% vs 7.1%, respectively). Weight gain in quitters with diabetes (1.7 kg) was similar to that of those without diabetes (2.1 kg). Conclusions: Varenicline was an effective and well-tolerated aid for smoking cessation in individuals with diabetes. Safety was comparable with participants without diabetes.