The authors report the results of a study intended to evaluate the prevalence of obesity in Italy. A population of 85,509 subjects (48.6% males, 51.4% females) distributed throughout the country was interviewed. Obesity was found in 5.5% of males and 6.4% of females. A map has been drawn up showing the distribution in age groups and territorial sectors. Indications for preventive and rehabilitative measures are given.