Between September 2005 and April 2006 we observed 20 nests and 42 nestlings of the tropical mockingbird, Mimus gilvus (Vieillot, 1808) in Villa de Leiva, Boyacá, Colombia. 40% of all nestlings (40% of the nests) showed some level of myiasis or subcutaneous infestation by fly larvae (Diptera: Muscidae). The larvae collected from one of the nestlings were reared and identified as Philornis vulgaris Couri 1984, constituting the first record for this species in Colombia.