A 5-year-old cat developed a recurrent haematoma in the right hindlimb after receiving an intramuscular injection. Cold packs and a compressive bandage were applied without success. The haematoma resolved initially but recurred twice within a week after conservative treatment. Contrast computed tomography was performed after the second recurrence. A large cavernous lesion was found craniolateral to the right stifle. The lesion was removed surgically. No recurrence occurred during a 5 month follow-up. On histopathology the lesion was characterised as a chronic expansive haematoma. To our knowledge, this type of lesion has not previously been described in a small animal.