Objective: Lymphocutaneous fistulas with intractable lymphatic leakage represent a serious clinical condition leading to a severe impairment of quality of life for the affected patients. To date, no adequate diagnostic imaging modality is in existence to allow selection of the correct treatment option. The aim of this study was to perform a pre-therapeutic evaluation of the lymphatic system in patients with lymphocutaneous fistulas by magnetic resonance lymphangiography (MRL). Methods: Eight lower extremities in four patients with lymphocutaneous fistulas were examined by MRL. Three locations were examined: first, the lower leg and foot regions; second, the upper leg and the knee region; and third, the pelvic and retroperitoneal regions. A T 1 weighted three-dimensional (3D) spoiled gradient echo and a heavily T 2 weighted 3D turbo spin echo (3D-TSE) sequence were utilised to undertake MRL. Results: In all four patients (100%), the clinically suspected lymphocutaneous fistulas (groin and forefoot) were exactly delineated by MRL. In two patients (50%) adjacent diffuse lymphangiomatous changes were detected, extending into the upper leg, pelvis, retroperitoneum, abdomen and abdominal walls. In one patient (25%) with primary lymphoedema of the right lower extremity, MRL revealed an aplasia of the lymphatic collectors at the levels of the lower and upper leg. All patients (100%) suffered from an ipsilateral lymphoedema of the lower extremity, whereby in two patients with diffuse lymphangiomatosis the lymphatic vessels were consecutively enlarged up to a diameter of 6 mm. Conclusion: MRL is a safe and accurate imaging modality for a comprehensive evaluation of the lymphatic system in patients suffering from lymphocutaneous fistulas.