Therapy with medicinal leeches (Hirudo medicinalis) is now frequently applied in plastic surgery and in the management of chronic venous insufficiency. We observed a patient in whom firm, brown-red, pea-sized papules developed at each site where leeches had been applied on the lower legs. Histology, immunohistology, and molecular analysis of T-cell receptor and immunoglobulin heavy chain gene rearrangement proved these lesions to be follicular pseudolymphomas. (J Am Acad Dermatol 2000;43:867-9.)