This pilot study was designed to assess the short-term effectiveness and side effects of methylphenidate in treating symptoms of attention deficit hyperactivity disorder (ADHD) in Native American children (5 to 12 years old) with documented fetal alcohol syndrome (FAS) or partial fetal alcohol syndrome. Using strict criteria for the diagnosis of FAS and ADHD, a randomized double-blind cross-over study of two placebos and a fixed dose of methylphenidate was completed in 4 Native American children in a residential school. Each treatment condition lasted 5 days, and daily observational outcome measures, the Conners Parent Rating Scale (CPRS-48), and the Conners Teacher Rating Scale (CTRS-39), were employed. Methylphenidate significantly improved scores of the Hyperactivity Index Scale on the CPRS-48 and the CTRS-39 but not the Daydreaming-Attention score on the CTRS-39. Side effects were similar to those traditionally found in other populations. The promising preliminary results suggest that a more definitive study of methylphenidate in Native and non-Native children with FAS and ADHD is warranted.