The relationship of body mass index, body fat, waist to hip ratio, fasting blood glucose and sum of blood glucose levels during oral glucose tolerance test with casual blood pressure (BP) and BP parameters obtained by 24h ambulatory BP monitoring in 97 out-patients moderately obese (66 with android type obesity), normal glucose tolerance and mild hypertension at entry study, has been evaluated. A negative correlation between body mass index and systolic ambulatory BP levels as the 24h mean, daytime and nighttime, has been documented in all of the obese subjects; no correlations between body mass index and casual BP were shown. Only in the group of android type obese was the body mass index correlated positively with the casual DBP. Systolic 24h and nighttime BP values correlated positively with waist to hip ratio; the correlation coefficients improved in the subgroup of android type obese. By using 24h ambulatory BP monitoring, it may be possible to show that waist to hip ratio is a better predictor of systolic hypertension than other parameters such as those derived from weight and height measurements and body fat percentage.