In order to evaluate the influence of regular non-strenuous physical exercise on the appearance of microalbuminuria in Type 2 (non-insulin-dependent) diabetic patients, we have studied a cohort of 372 Type 2 diabetic patients (152 males and 220 females, mean age: 63.59 +/- 0.70 years, evolution time: 10.31 +/- 0.4 years, M +/- SEM). One hundred and ninety seven (52.9%) presented normo-albuminuria, 124 (33.3%) microalbuminuria and 51 (13.7%) proteinuria. These three groups were different with regard to evolution time, weight, BMI, waist-hip ratio, Hb1Ac value, prevalence of hypertension and physical activity level. 132 (35.4%) patients had a regular exercise-induced caloric expenditure under 500 kcal/wk whereas 122 (32.7%) were between 500 and 1.000 kcal/wk and 118 (31.7%) over 1.000 kcal/wk. Prevalence of normo-albuminuric patients was 40.1%, 52.4% and 67.7% respectively (p < 0.01). Prevalence of normo-albuminuric patients remained significatively higher in the patient with the greater physical activity level when adjusted to systolic blood pressure, diastolic blood pressure, evolution time and HbA1c value. Our results stress the fact that regular non-strenuous physical activity may have a protective effect on the appearance of microalbuminuria in Type 2 (non-insulin-dependent) diabetic patients. Whether the cardiovascular protective influence of exercise in these patients depends on such an effect remains unknown. On the basis of this cross-sectional evidence, a longitudinal study is now under way.