Massive ovarian oedema is an unusual clinical entity occurring in teenage girls. It is a rare tumour-like condition of the ovary characterized by marked enlargement of one or both ovaries due to marked accumulation of oedema fluid in the ovarian stroma. Massive ovarian oedema may result from partial or intermittent torsion of the mesovary, interfering with venous and lymphatic drainage, but not with arterial blood flow. The patients most commonly present with lower abdominal pain and enlargement. This entity can clinically mimic a neoplasia. We report three cases with massive ovarian oedema.