Benzylpiperazine is a psychotropic compound that has been widely available until recently from licensed premises such as ‘head shops’. This report describes a case of a 48 year old man with schizophrenia who developed an acute delirium secondary to benzylpiperazine use, although he initially presented as a diagnostic conundrum. Investigation of his delirium unearthed a temporal meningioma which appears to be an incidental finding. This is the first documented case of delirium due to benzylpiperazine use. Benzylpiperazine has significant abuse potential and psychiatric complications. Its sale and possession have recently been made illegal in Ireland, which may limit its abuse in the future.