To evaluate the effect of a multimedia education program and nutrition therapy on metabolic control in patients with type 2 diabetes. What is the effect of a multimedia education program and nutritional therapy on metabolic control in type 2 diabetes? A randomized clinical trial was conducted in 351 patients randomly assigned to either an experimental group receiving a multimedia diabetes education program (MDE) and nutrition therapy (NT) (NT + MDE: n = 173), or to a control group who received nutrition therapy only (NT: n = 178). At baseline, 7, 14, and 21 months, the glycated hemoglobin (HbA1c), glucose, cholesterol, triglycerides, LDL-cholesterol, and HDL-cholesterol were measured. Weight, body mass index (BMI), waist circumference (WC), fat percentage, fat and lean mass, systolic blood pressure (SBP), and diastolic (DBP) were also recorded. Glycated hemoglobin decreased in both groups, although the group with NT + MDE had a greater reduction, with a difference of -0.76% (95%CI -1.33 to -0.19) at 7 months and -0.73% (95%CI -1.37 to -0.09) at 21 months. Only in the NT + MDE did the glucose decrease at 7 (-41.2 mg/dL; 95%CI -52.0 to -30.5), 14 (-27.8 mg/dL; 95%CI -32.6 to -23.1), and 21 months (-36.6 mg/dL; 95%CI -46.6 to -26.6). Triglycerides and the atherogenic index decreased in both groups at 7 and 14 months; while only in the NT + MDE group did it decrease at 21 months. (p