Lymphangioma circumscriptum is characterized clinically by grouped vesicles, some of which may be filled with serosanguineous fluid. The depth and extent of involvement of lymphangioma circumscriptum cannot be adequately estimated from the cutaneous examination. We describe two patients with lymphangioma circumscriptum evaluated by magnetic resonance imaging. Magnetic resonance imaging accurately demonstrated the true extent of involvement. With magnetic resonance imaging to delineate the entire lesion of lymphangioma circumscriptum, one can (1) provide education to the family regarding the extent of involvement and (2) prevent incomplete invasive surgical procedures from being performed.