In order to assess M-mode echocardiographic recordings in a normal Norwegian population, 190 apparently healthy subjects (95 women and 95 men) aged 21-69 years were examined with an Irex Meridian system. Measurements were performed according to criteria recommended by the American Society of Echocardiography. Absolute values for all parameters except for left ventricular (LV) shortening fraction (SF) were greater in men (P less than 0.001). When corrected for body surface area (BSA), the differences between the two genders were far less pronounced. Women had greater left atrium (LA) (P less than 0.01) and LV end-diastolic diameter (EDD) (P less than 0.001), whereas the interventricular septum in end-diastole (IVS-ED) (P less than 0.05) and LV posterior wall (PW) in ED (P less than 0.001) were thicker in men. Only weak correlations between age and the various echocardiographic parameters with r-values less than or equal to 0.30 were observed. It is recommended that BSA corrected values should be preferred since the differences between men and women are negligible. When absolute values are used, different normal ranges for both sexes should be applied.