Diabetes mellitus (DM) is one of the most challenging health problems of the 21st century. About 422 million people have DM and by year 2035, this number is expected to reach 592 million. Pakistan with an escalating DM prevalence is expected to be among the top ten high burden diabetic countries of the world by year 2035. Today, with the global increase in the diabetic population there is a resurgence of interest in the dual epidemic of DM and tuberculosis (TB). Pakistan ranks 4th in terms of global burden of TB with an estimated incidence of 231 cases per 100,000 population. DM increases the risk of developing TB, delays sputum conversion, increases risk of failure of treatment, death, recurrence and relapse. There is scarcity of data regarding the impact of diabetes on TB treatment outcomes in Pakistan. This prospective cohort study was conducted in October 2013 at Gulab Devi Chest Hospital, Lahore, Pakistan to estimate the risk of adverse outcomes in diabetic patients who were being treated for TB. A total of 614 pulmonary tuberculosis (PTB) patients were recruited and screened for DM through random and fasting blood glucose tests; and based on the results were divided into exposed (diabetic) and unexposed (non-diabetic) groups. Both groups were followed up at 2, 5 and 6 months during anti-tuberculosis treatment (ATT) and 6 months after ATT completion to determine treatment outcomes. Of the total, (n= 113 (18%) were diabetic and (n= 501 (81%) non-diabetic. About half of them i.e. (n= 323 (52%) were illiterate with mean age of 32±15 years. The final multivariate analysis showed that diabetics were more likely to experience an unfavorable outcome as compared to non-diabetics (OR= 2.70, 95% CI= 1.30 to 5.59, p = 0.008), after adjusting for age, residential background, smoking status and body mass index (BMI). Other independent predictors of unfavorable outcome were identified as rural area of residence (OR= 1.98, 95% CI =1.14 to 3.47, p = 0.008), BMI less than 18.50 (OR=1.89, 95% CI=1.03 to 3.47, p=0.041) and being a smoker (OR=2.03, 95%CI=1.04 to 3.94, p=0.037). Kaplan Meier survival analysis showed that survival among the diabetic PTB patients was significantly lower as compared to the non-diabetic PTB patients. The final multivariate Cox regression analysis showed that diabetics had decreased survival compared to non-diabetics (aHR=2.52, 95%CI=1.02 to 6.23, p=0.045) after adjusting for age, BMI and smoking status. Other independent predictors of death as treatment outcome were found to be age (aHR=1.03, 95%CI= 1.01 to 1.06, p=0.004) and a BMI of less than 18.50 (aHR=3.26, 95%CI=1.33 to 8.01, p=0.010). Our study has documented adverse treatment outcomes among diabetic PTB patients as opposed to non-diabetic PTB patients. DM was found to be associated with unfavorable treatment outcome and a decreased survival among PTB patients. As the way forward we propose an emerging framework for the transfer of research results into policy and practice based on the systematic review undertaken by us. A comprehensive integrated program for the co-management of TB and DM needs to be initiated.