OBJECTIVES: To evaluate the efficacy and safety of methylphenidate compared to other pharmacological alternatives or placebo in the treatment of ADHD. METHODS: Health technology assessments (HTA), randomized clinical trials (RCT) or systematic reviews (SR) of RCT were systematically researched. Inclusion criteria were placebo or pharmacological intervention as comparators, and children or adolescents as population. Studies about different dosis or presentations of methylphenidate were also selected. RESULTS: One ECR, four SR and two HTA were selected comparing methylphenidate to placebo, atomoxetine, buspirone, dexamphetamine. Methylphenidate was superior to placebo in the index of hyperactivity detected by parents and teachers, behavior during the execution of tasks, productivity in classroom and in precision of the activities. Response rates to treatment and abandonment were better as compared to atomoxetine. Compared to buspirone, methylphenidate was shown to be more effective in reducing the symptoms of ADHD. Benefits of methylphenidate on dexamphetamine are inconclusive. Low dose methylphenidate was superior to high dose in behavior improvement on the execution of tasks. There was no difference between long and short acting presentations. Regarding security: anorexia, insomnia, migraines, stomach pain and dizziness were often associated with methylphenidate. CONCLUSIONS: Primary studies showed methodological limitations such as low quality, short follow up and low capacity of generalization. The evaluation of the results should be cautious. It is necessary to find a balance between benefits and risks before starting the administration of methylphenidate in children and adolescents, especially in long-term treatments.