Objective: To investigate the prevalence of type II Diabetes Mellitus (DM) and impaired glucose tolerance (IGT) and identify the metabolic abnormalities and risk factors associated with these conditions in an urban city of Yemen.Research Design And Methods: Cross-sectional, population-based study investigating 498 adults (245 males and 253 females) aged 25-65 years. The 1999 modified World Health Organization criteria were adopted for the diagnosis of Diabetes Mellitus and IGT. A standard questionnaire was applied and blood lipids, blood pressure, body mass index (BMI) and waist/hip ratio (WHR) were determined.Results: The overall prevalence of type II Diabetes Mellitus was 4.6% (7.4% in males and 2% in females). Impaired glucose tolerance (IGT) and impaired fasting glucose (IFG) were found in 2% and 2.2% of the study population. Factors independently related to any abnormality in glucose tolerance, using logistic regression analysis, were sex, hyperlipidaemia, hypertriglyceridaemia, and hypertension; whereas sex and age related to DM. More than 80% of the type II diabetics were over the age of 40, 35% being hyperlipidaemic, 22% being hypertensive and 18% obese. Sixty percent of IGT subjects were hyperlipidaemic and 20% were obese. Approximately 78% of obese individuals (>/=30 kg/m(2)) had normal glucose tolerance.Conclusion: The prevalence of type II DM and its potential increase reflected by the high prevalence of obesity in normal glucose tolerance subjects in the Yemeni population constitutes a major public health problem.