Obesity is a known risk factor of cholecystolithiasis. The potential causes of increased incidence of cholecystolithiasis in people with obesity (overweight) and in those with normal body mass are considered. The study involved 100 patients with diagnosed cholecystolithiasis hospitalized in one of the randomly selected hospitals in Bialystok and its vicinity. The questionnaire technique was used to evaluate risk factors of cholecystolithiasis. It was found that women, irrespective of body mass, were 2.7 times more often hospitalized due to this ailment than men. Of the patients examined, 71% had overweight or obesity. Women with normal body mass suffered from cholecystolithiasis at the younger age than the obese or overweight ones. The comparison of risk factors of cholecystolithiasis between the obese (overweight) patients and those with normal body mass revealed a significantly more frequent familial incidence of type 2 diabetes and cholecystolithiasis. Patients with cholecystolithiasis, irrespective of body mass, were characterized by low intake of dark bread and wholemeal products, raw fruit and vegetables, and pulses. Obese women with cholecystolithiasis significantly more frequently consumed milk and yoghurt, meat and its products, lard, bacon and sweets than women with normal body mass. Obese men (with overweight) significantly more frequently consumed high-fat foods than the slim ones.