Background: Classic Rett syndrome (RS) has been described in females only. Although an X chromosome origin is probable, it has not been substantiated. It is possible therefore that RS could occur in males. Method: Case report of a male with RS and review of all the reported cases in the literature. We compare our case to the other cases, and examine the applicability of the classic RS diagnostic criteria to this variant. Results: To date, nine cases of male RS have been reported. We describe a further male who met 7 of 9 necessary criteria and 6 of 8 supportive criteria as defined by the RS Diagnostic Criteria Work Group. When we apply these criteria to the other 9 reported cases, many necessary inclusion criteria were not met despite the absence of exclusion criteria. The supportive criteria were even more variable and limited in many cases. Conclusions: Males with RS appear to represent a heterogeneous phenotype, with clinical features that may meet many but not all of the necessary diagnostic criteria of classic RS. Less restrictive criteria are needed to include this variant which should be considered when evaluating males with idiopathic developmental regression, autistic features, and loss of hand function.