Background: The merging epidemics of pulmonary tuberculosis (PTB) and diabetes mellitusrn(DM) have been raised concerns by many experts but no large scale screening andrnintervention have been launched yet, especially in low-income countries like Ethiopia. Thernthought that tuberculosis could cause diabetes seems farfetched, but is not. The peculiarrnrelationship and frequent association of diabetes mellitus and tuberculosis has been observedrnfor more than 2000 years, yet the reason for this correlation is, to this day, not known.rnObjective: the aim of this study was to determine the prevalence of diabetes mellitus amongrnactive PTB patients at St.Peter hospital.rnMethods/design: A cross-sectional Hospital based study was carried out and the studyrnincluded all active pulmonary tuberculosis patients visiting St. Peter specialized hospital untilrnthe required sample size was obtained. We included 120 active PTB patients: 67 of these werernmale and 84 of them were urban dwellers. Analysis of fasting blod glucose was carried outrnusing venous blood samples by enzymatic colorimetric test for glucose (GOD-PAP Method).rnFor testing significance, the categorical data were compared using a chi-square test andrnexpressed as proportion with a 95% confidence interval.rnResult: The prevalence of DM was found to be 15.8% (95% CI:9.20-22.45), which was higherrn(25.4%) among male than female TB patients(3.8%).Likewise 70% of the patients were fromrnurban and 30% of them were from rural areas. The prevalence of newly diagnosed diabeticrncases was 84.2% of all patients tested positive for DM. And all of the patients diagnosed asrndiabetic were in the age group greater than 25 years of age. The prevalence of IFG wasrn(26.7%) and that of HIV co-infection in the study population was (52.5%). The occurrence ofrnDM in HIV co-infection was a little bit higher (15.9%) than HIV negative TB patientsrn(15.8%). Of all patients with active tuberculosis, 60 (50%) were sputum smear negative. Thernproportion of DM was (25%) among smear positive and (6.7%) among smear negativernpatients.rnConclusion: The prevalence of diabetes mellitus and pre-diabetes (IFG) among activernpulmonary tuberculosis cases was higher compared to the published prevalence of DM inrnEthiopia. Therefore, it is important to implement a screening program of each TB patient forrndiabetes and Vis versa.rnKey words: TB/DM, IFG, HIV co-infection