BackgroundMetabolic syndrome is one of the most serious global public health problems. It is associated with a higher risk of heart attack and other cardiovascular diseases. However, the magnitude of metabolic syndrome among patients with type 2 diabetes mellitus is not well understood, especially in developing countries such as Ethiopia.ObjectiveTo determine the magnitude of metabolic syndrome and associated factors among type 2 diabetes mellitus patients at Adama Hospital Medical College, Ethiopia, in 2022.MethodA facility-based cross-sectional study was conducted from September 1 to October 30, 2022. The data was collected through a self-administered questionnaire. A systematic random sampling method was used to select the participants. Data were entered using Epi Info version 7.2 and analyzed by SPSS version 23. Multivariable logistic regression was used to model this study. Statistical significance was set at p-values of < 0.05.ResultA total of 237 participants were included in this study, with a response rate of 95.1%. Overall, the magnitude of metabolic syndrome was 53.2% (95% CI: 46.8 - 59.6), 41.3% (95% CI: 35.0 - 47.5), and 41.8% (95% CI: 35.5 – 48.1) based on 2009 harmonized criteria of MetS, Revised National Cholesterol Education Program Adult Treatment Panel III (NCEP-ATP III), and International Diabetes Federation (IDF) criteria, respectively. In multivariable logistic analysis, urban residence (AOR=3.07, 95% CI: 1.46-6.42), earning a high income (AOR=5.87 95% CI: 1.8-19.1), history of cardiac illness (AOR=3.33, 95% CI: 1.41-7.84), history of hypertension (AOR=2.65, 95% CI: 1.22-5.78), dyslipidemia (AOR=4.47, 95% CI: 1.96-10.19), current cigarette smoker (AOR=6.2, 95% CI: 1.7-22.93), sedentary activity (AOR=3.62, 95% CI: 1.68-7.82), use of palm oil (AOR=4.87, 95% CI: 2.06-11.51), and BMI ≥25 kg/m2(AOR=3.36, 95% CI: 1.57-7.16) were significantly associated with metabolic syndrome.ConclusionThe findings of this study suggested that the magnitude of metabolic syndrome among T2DM patients was high. We found consistent results using the NCEP-ATP III and IDF criteria. Similarly, urban residence, high income, history of cardiac, history of hypertension, dyslipidemia, current cigarette smoker, sedentary activity, palm oil, and BMI ≥25 kg/m2were significantly associated with metabolic syndrome.