We conducted a pilot study to assess the feasibility of a web-based therapy management system with mobile phone access to support obese patients. A total of 25 patients participated in the study. The mean age of the patients was 48 years. The mean body mass index of the patients at recruitment was 35.6 kg/m(2). The mean observation period was 70 days. A total of 361 successful data transmissions was performed -- the mean number of transmissions per patient was 14. The total number of outgoing reminder messages was 123, corresponding to 4.9 reminder messages per patient. At the end of the study, there were significant reductions of 2.4 cm in abdominal girth (P < 0.001), 2.4 kg in bodyweight (P < 0.001) and 0.78 kg/m(2) in body mass index (P < 0.001). In a questionnaire at the end of the study, the majority of the participants gave answers that indicated a positive attitude towards the system. The pilot study showed that mobile phones can be utilized as patient terminals for therapy in patients suffering from obesity.