Adipose-derived therapies have increased in popularity for treatment of painful orthopaedic conditions, such as osteoarthritis. We report the passage of fat into a Baker’s cyst after injection of micro-fragmented adipose tissue in a patient with bilateral knee arthritis. Following fat grafting, the patient required drainage of fatty fluid from within the Baker’s cyst on multiple occasions. Approximately 3 months postprocedure, she began to notice an improvement in her knee pain with no further recurrence of pain or swelling from her Baker’s cyst.