Introduction: The deciduosis is the more typical colposcopy picture of pregnancy. This term indicates a decidual ectopia. Objective: To present the clinical case of a pregnant presenting with a cervical lesion led to an ulcerated deciduosis. Results: By means of a colposcopy and later by a punch biopsy the diagnosis of ulcerated deciduosis was confirmed in a pregnant of 22.5 weeks. Conclusions: In front of that each pregnant with a cervical lesion suspected or not of malignancy, the colposcopy could be used as a diagnostic method provided that