Widespread evidence has demonstrated the negative effects of tobacco smoking in patients with diabetes. Although many studies have explored the prevalence of tobacco smoking in the general population, data are lacking regarding its prevalence in a specific population with a chronic disease such as diabetes. OBJECTIVES This study aims to determine the prevalence of tobacco smoking among patients with diabetes in Hospital Pulau Pinang, Malaysia. METHODS A cross-sectional survey was conducted to study diabetic patients who attended the endocrine clinic at Hospital Pulau Pinang in Malaysia from March to August 2012. All the diabetic patients who attended the endocrine clinic during that period were asked about their smoking status, and their medical records were reviewed. A total of 1,118 patients with diabetes were reviewed to determine the prevalence of tobacco smoking in diabetic patients at the endocrine clinic of Hospital Pulau Pinang. RESULTS The majority of the study population was male, with Malay and Chinese patients in almost equal proportions and a smaller proportion of Indian patients. Most of these patients had started smoking before they were diagnosed with diabetes. Among the 1,118 diabetic patients, only 108 patients smoked; therefore, the prevalence of tobacco smoking in our patients with diabetes was 9.66%. CONCLUSIONS A low prevalence of tobacco smoking was estimated in this study. This prevalence is close to the corresponding value in the general population in Malaysia.