In a retrospective study of 1566 cases of pulmonary tuberculosis, 136 were found to have diabetes mellitus for a prevalence of 8.7%. There were 100 males and 36 females, and the average age patient age was 52 years. Saudis accounted for 94 (69%) of the cases. The prevalence of diabetes was 13% for Saudi patients as compared with 5% for non-Saudis (P < 0.005). Sputum conversion took an average of 46 days. There was a 19% prevalence of lower lung field lesions. Ninety-three (68.4%) patients were on insulin therapy, 25 (18.9%) were on oral hypoglycemics, and 18 (13.2%) were managed on diet alone. Of 104 patients who were sputum positive, 100 showed conversion after treatment with first-line antitubercular drugs. There was no statistically significant difference in the sputum conversion between diabetic and nondiabetic patients.