3,4-methylenedioxymethamphetamine (MDMA), known as ecstasy, is a hallucinogen and stimulant illicit drug. Besides the systemic effects of this drug are well documented, it can also present with a range of oral side effects such as ulcerations, and to our knowledge, there are only a few cases involving oral mucosal ulcerations related to MDMA abuse in the literature. We encountered a 38-year-old man with widespread and multiple oral ulcerations attributed to MDMA abuse. We would like to raise awareness about that this kind of ulcers may be associated with ecstasy use, and it should be included in the differential diagnosis.