Our aim in this prospective study was to determine the impact of laparoscopic sleeve gastrectomy on the quality of life of patients with morbid obesity in comparison with population standards. The study evaluated 76 morbidly obese patients who underwent laparoscopic sleeve gastrectomy. The short version of the World Health Organization Quality of Life questionnaire (WHOQOL-BREF) was used to evaluate quality of life in the following four areas: physical health, mental health, social relations, and environment. Patients completed the questionnaire before their planned operation and again 3 and 6 months after surgery. Compared with the population standard, patients with morbid obesity had significantly lower quality of life scores in the physical and mental health domains, including on independent questions related to of overall health and quality of life (p<0.001). Women scored lower on indicators of mental health than men. Three and 6 months following surgery a significant trend of body mass index (BMI) reduction was seen, as well as increased quality of life in all indicated areas (p<0.001). Laparoscopic sleeve gastrectomy treatment in morbidly obese patients reduced BMI on a long-term basis, a change seen as early as 3 months after surgery. By 6 months after surgery, patients had the same quality of life scores as the reference population.