A 60-year-old woman complained about an indolent and slowly growing tumor of the vulva. Clinical examination showed a sharply circumscribed lump in the posterior part of the left labium majus, suggestive of a cyst of Bartholin's gland. At operation a solid, macroscopically encapsulated tumor was found, which was a mostly well-differentiated liposarcoma on histological examination. Ten months after operation, the patient was well and had no signs of local or distant recurrence. The clinical and pathological features of this extremely rare case are presented and discussed.