INTRODUCTION Ecstasy, also known as MDMA (3,4, methylenedioxymethamphetamine), is a popular illicit party drug amongst young adults. The drug induces a state of euphoria secondary to its stimulant activity in the central nervous system. PATIENTS AND METHODS A database review at two major inner city hospitals was undertaken to identify patients presenting with pneumomediastinum and their charts reviewed. A Medline review of all reported cases of pneumomediastinum associated with ecstasy abuse was undertaken. RESULTS A total of 56 patients presenting with pneumomediastinum were identified over a 5-year period. Review of the charts revealed a history of ecstasy use in the hours prior to presentation in six of these patients, representing the largest series reported to date.CONCLUSIONS Review of previously reported cases reveals the likely mechanism is due to Valsalva manoeuvre during periods of extreme physical exertion, and not a direct pharmacological effect of the drug. KEYWORDSMediastinal emphysema -N-Methyl-3,4-methylenedioxyamphetamine -Ecstasy