Acute renal infarction is a well known, although relatively unfrequent, cause of flank pain resistant to administration of spasmolytic and nonsteroidal anti-inflammatory drugs. We present an original case of a 41-year-old man, complaining of acute severe left flank pain, resistant to common analgesic therapy, who was diagnosed of segmental renal infarction of a branch of left renal artery. Pathophysiology of renal damage in cocaine users is multifactorial, and it has been postulated that the right kidney was more prone to ischaemia. Left kidney represents an extremely unusual site of cocaine-related renal infarction.