Myiasis is a disease caused by an infestation of the tissues of vertebrates by developing fly larvae. We document the first cases of human myiasis by Lucilia cuprina (Wiedemann, 1830) in Rio de Janeiro, Brazil, analyzed the epidemiological and clinical profiles of the patients, and their risk factors associated with the occurrence of the disease. Between May 2008 to July 2013, six cases of myiasis caused by larvae of L. cuprina were reported in patients treated in the Federal Hospital of Andaraí, Rio de Janeiro, Brazil. The six patients ranged between 13 and 72 yr old, belonged to various ethnic groups, and both sexes were represented. The affected individuals were relatively uneducated, had low income and poor hygiene habits. Infections were more common in the legs. The following factors were found to predispose individuals to myiasis: trauma, pediculosis, erysipelas, skin infections, and wounds resulting from congestive heart failure. Myiasis by L. cuprina occurred predominantly in the summer when there is abundant rainfall.