OBJECTIVES To evaluate compliance with drug treatment in patients with metabolic syndrome as well as weight loss and physical activity practicing during a 12-month follow-up. METHODS This was a longitudinal study, with a 12-month follow-up, involving 45 patients with metabolic syndrome according to IDF criteria, who were being treated in a Health-Medical School Center under the Brazilian Healthcare System. Patients were evaluated every three months. The Measure Treatment Adherence, a variation of the Morisky-Green Test, in a 1 to 6 scale, was used to assess patient behavior patterns associated with the use of medicines. Parameters to evaluate compliance with non-drug treatment were: to achieve a 10% weight reduction in total body weight and to perform a minimum of 30 minutes of physical activity at least three times a week. RESULTS Average levels of compliance in each measurement were: 5.49 ± 0.44 (at inclusion); 5.68 ± 0.57 (3-month follow-up); 5.87 ± 0.28 (6-month follow-up); 5.79 ± 0.44 (9-month follow-up); 5.72 ± 0.46 (12-month follow-up). At the end of 12-month period, four patients achieved weight reduction goal. Average % weight variations in relation to the established goal were: ª10.2% ± 2.9 (3-month follow-up); ª10.0% ± 6.5 (6-month follow-up); ª10.1% ± 7.2 (9-month follow-up); ª10.5% ± 7.5 (12-month follow-up). Patients who practiced no physical activity were: 62% (at inclusion); 60% (3-month follow-up); 64% (6-month follow-up); 69% (9-month follow-up); 69% (12-month follow-up). The majority of patients who practiced physical activities spent more than 30 minutes per exercise session. CONCLUSIONS Patients involved in this study exhibited a high level of compliance with drug treatment. More research is needed to confirm if this result is characteristic of patients treated in a Health-Medical School Center. Although regular practice of physical activity and weight loss are associated with significant clinical improvements, both these issues need to be better addressed.