Background and study aims Incidence of morbid obesity has grown dramatically in the last half century and this phenomenon affects with particular severity the pediatric population. Dietary restrictions and careful programs to improve lifestyle are often ineffective to manage this particular group of patients, due to poor compliance typical of the adolescence. The aim of this study was to evaluate the effectiveness of a new intragastric balloon for treatment of morbidly obese children. Patients and methods A new swallowable intragastric balloon (Obalon) has been used for the first time in 17 obese children in order to assess its safety and effectiveness in terms of reduction in excess weight. In 9 of 17 children a second balloon was placed 30 to 40 days after the first insertion. All devices were endoscopically removed after a mean time of 18 weeks. Results In the group of 16 patients who completed the study (1 patient still under treatment) mean weight decreased from 95.8 ± 18.4 Kg to 83.6 ± 27.1 (P < 0.05). Mean body mass index (BMI) decreased from 35.27± 5.89 (range 30.4 - 48) to 32.25 ± 7.1 (range 23.5 - 45.7) (P > 0.05); mean excess weight, calculated according to Cole's curves for pediatric populations, decreased from 36.2 ± 15.9 to 29.4 ± 18.3 Kg (P = 0.14), with an %EWL of 20.1 ± 9.8 (range 2.3 - 35.1). Waist circumference decreased from 109 ± 12.3 cm to 99 ± 10.5 cm (P < 0.05). Conclusions Obalon can be administered easily without complications, inducing an appreciable weight loss with a statistically significant reduction in BMI and an improvement in associated comorbidities.