We report 4 patients diagnosed of metastatic colorectal cancer, treated with chemotherapy: 5-fluoracil (5FU), folinic acid and oxaliplatin, De Gramont schedule (FOLFOX 6 modified), who showed fever of drug-related origin, probably due to oxaliplatin infusion. The four patients repeatedly underwent microbiological studies, and infectious pathology was ruled out.All events were self-limited and started during or soon after oxaliplatin infusion. They weren't reported in the first cycle of treatment, but they were repeated in every cycle after the first occurrence of fever, in three of four patients. The efficacy of antipyretic drugs was very limited, as much during febrile events as during the attempts to prevent them.We consider it likely that, in this group of patients, there was a cause-effect relationship of oxaliplatin-induced fever, although at the moment we don't know the exact trigger mechanism.