Leclercia adecarboxylata is a Gram-negative bacillus of the Enterobacteriaceae family. Considered a rare bacterium in clinical practice, it is an opportunistic microorganism found in aquatic environments, whose infectious action tends to be limited to immunocompromised patients. This work aims to describe a case of an infected lesion by Leclercia adecarboxylata in a patient with chronic comorbidities. A 71-year-old male patient, fisherman, from Turiaçu–MA, sought medical care due to a left leg wound with a five-month evolution. The condition began after trauma with a sharp object during work activities. Initially, the lesion presented a bullous appearance, with slight drainage of clear (hyaline) secretion and mild pain associated with inflammatory signs (warmth, erythema). Subsequently, it evolved into a dry aspect, though without complete remission. Past medical history included systemic arterial hypertension (on losartan 50 mg/day) and Diabetes Mellitus with inadequate glycemic control (glycated hemoglobin 7.9%), on metformin 850 mg/day. Before this consultation, he had used Diprosalic, Micolamina and fluconazole, with mild improvement. Perilesional scraping was requested to investigate leishmaniasis, given the characteristics of the ulcerated lesion, as well as a bacterial secretion culture. The result for Leishmania sp. was negative, but culture revealed growth of Leclercia adecarboxylata, which was sensitive to ciprofloxacin. Antimicrobial treatment was started with ciprofloxacin 500 mg every 12 hours. After seven days, the patient returned for reassessment, and the lesion showed significant improvement; he was instructed to continue treatment for one additional week. The patient remains under outpatient follow-up with good prospects for complete healing. Counseling was reinforced regarding appropriate control of Diabetes Mellitus, since the hyperglycemic state impairs the healing process. This factor, together with the rarity of the isolated pathogen, may explain the prolonged course of the wound.