The determination of microalbuminuria is a valuable method in the diagnosis of renal and vascular diabetes or hypertension complications. Recently, microalbuminuria appeared to be the predictor of coronary heart diseases (CHD). The presented study comprised 26 patients with stable angina pectoris (AP) and 27 healthy volunteers. We simultaneously evaluated microproteinuria during the first morning and afternoon miction and the 24-h blood pressure. Amongst patients with AP all urine protein concentrations were increased (results in g/mol creatinine): alpha-1-microglobulin (1.04 + 0.13 vs. 0.47 + 0.05, p < 0.001) albumin (0.95 + 0.15 vs. 0.61 + 0.05, p < 0.05) and IgG (1.00 + 0.17 vs. 0.55 + 0.05, p < 0.01) were higher, in comparison to control group values. Indices for diurnal blood pressure rhythm were significantly lower in the AP group for both systolic (1.07 + 0.01 vs. 1.14 + 0.01 p < 0.001) and diastolic (1.09 + 0.02; vs. 1.21 + 0.03 p < 0.01) pressures. A physiological increase of albumin from the afternoon sample was only observed in the control group. Thus, our AP patients demonstrated signs of subclinical nephropathy in both the proximal tubuli and glomeruli.