Obesity is a major risk factor for several chronic diseases, but the burden associated with it also extends to psychosocial areas and to perceived health status. In 1999 an observational study on health-related quality of life in obesity was planned. The study was entirely web-based. Case Report Forms and the individual items of 7 self-administered questionnaires were directly implemented on a general database via an extranet system from 25 Italian centers. By December 2001, after enrolment had stopped, the database included anthropometric, socioeconomic and clinical data of 1944 patients (78% females). Weight-cycling was reported in over 80% of cases, overeating in 60-65%, structured physical activity in only 13-15%. Several chronic illnesses were associated. Whereas the prevalence of diabetes and hypertension was related to the degree of obesity, hyperlipidemia and coronary heart disease did not increase further with increasing obesity. A disturbed psychological mood was twice more common in females. Concern for present health was the main reason for seeking treatment in both genders; concern for body appearance was more common in females. Male subjects were more frequently assigned to dietary counseling and physical exercise, whereas in females psychotherapy was more frequently considered. Various forms of behavioral approach were planned in approximately 50% of patients. Finally, very few patients were initially considered for pharmacological intervention or bariatric surgery. The study provides a comprehensive picture of Italian patients seeking treatment for obesity. Data on perceived health status, psychological well being, body image awareness, eating behavior disorders and psychopathological distress will provide clues to a comprehensive assessment of obesity, the effects of treatments and reasons for failure.