Unlabelled: Methylphenidate (MPH) is a potential therapeutic tool for Attention Deficit with Hyperactivity Disorders (ADHD). In addition to the immediate-release formulation, Ritalin, two extended-release formulations, Ritalin LA and Concerta are available and allow a once-daily administration. We compared the respective benefits of both formulations for the patients and their family in terms of efficacy, handling and tolerance., Patients and Methods: This prospective study was based on 30 children aged 6 to 15 years. All patients had a confirmed ADHD and were efficiently treated with Ritalin. The children were consecutively treated with Ritalin LA and Concerta, with a comparable MPH daily dosage, during 2 months for each molecule. The 3 drugs were evaluated individually and comparatively through a battery of questionnaires submitted to the parents and the teachers of each child., Results: Extended-release MPH efficacy was comparable to the immediate-release formulation, Ritalin. For both of them, the once-daily administration appeared beneficial. Concerta was finally prescribed in 18 children, Ritalin LA in 8 cases and Ritalin in 4 cases. In each case the medical choice was consistent with the parents preference. Concerta was appreciated for its persisting efficacy in late afternoon during homework. Concerta and Ritalin LA did not induce significant adverse effects, especially regarding alimentation and sleep., Conclusions: MPH therapy in ADHD carries an excellent risk/benefit ratio without addictive induced behaviours. The extended-release MPH formulations provide an improvement for the patients in keeping with Ritalin efficacy through a once-daily administration. Regardless of its formulation, MPH indications and guidelines must be respected.