This study aims to report the diagnostic course and treatment of a fast-growing mycobacteria infection after cesarean delivery. We report the case of a 37-year-old woman admitted to the Infectious Diseases' Clinic of the Hospital das Clinicas da Universidade Federal de Pernambuco, Pernambuco State, Brazil, four months after a cesarean section, presenting with healing difficulties and located pain outside the surgical site. The first diagnosis was a probable rejection of the sutures that were not absorbed, but based on the clinical signs, reported history, complementary laboratory tests and no response to treatment with the conventional antibiotic therapy (cephalosporins/quinolones) prescribed, the ultimate diagnosis was a mycobacteriosis caused by Micobacterium fortuitum. Since fast-growing mycobacteria do not easily penetrate host tissues, they is mainly related to post-trauma or post-surgical procedures. It is extremely important to call attention to these occurrences in the gynecological-obsthetric field. Treatment for mycobacteriosis is often complicated because of the side effects of antibiotics, especially the ototoxicity of amikacin.