Background- Type 2 diabetes mellitus (T2DM) is a prevalent chronic disease requiring effective long-term management strategies to prevent complications. Our study compares the long-term effectiveness of lifestyle interventions versus pharmacotherapy in managing T2DM. Methods- A one-year randomized controlled trial was conducted with 60 T2DM patients, divided equally into a lifestyle intervention group and a pharmacotherapy group. The lifestyle group received dietary, physical activity, and behavioral therapy guidance, while the pharmacotherapy group was treated with standard diabetes medications. Key outcomes measured included HbA1c, BMI, cardiovascular health indicators (blood pressure, lipid profiles), and quality of life. Results- The lifestyle intervention group showed a significantly greater reduction in HbA1c (-1.5% vs. -1.1%, p=0.03) and BMI (-1.9 kg/m² vs. -0.5 kg/m², p=0.01) compared to the pharmacotherapy group. Improvements in cardiovascular health indicators were also more pronounced in the lifestyle group, with greater reductions in systolic and diastolic blood pressure, LDL cholesterol, and higher increases in HDL cholesterol. Quality of life scores increased significantly more in the lifestyle group (+13.6 vs. +7.8, p=0.02). Conclusion- Lifestyle interventions are more effective than pharmacotherapy in improving glycemic control, reducing BMI, enhancing cardiovascular health, and improving quality of life in T2DM patients. Integrating lifestyle modifications into diabetes care can significantly enhance treatment outcomes.