Background: Mucormycosis is a rare infection caused by ubiquitous fungi of the Mucorales order that mainly affects immunocompromised patients. These fungi have an important tropism for blood vessels that allows them to spread rapidly and cause thromboembolic events. Case report: We present a case of an 8-year-old male patient diagnosed with acute lymphoblastic leukemia treated with chemotherapy. He presented icteric syndrome, hepato-splenomegaly, and data of intestinal obstruction. Although he underwent intestinal resection, he did not improve and died. The autopsy identified disseminated mucormycosis involving the brain, lungs, esophagus, small intestine, colon, and pancreas. Conclusions: Hematological neoplastic diseases and their treatment are important risk factors for developing infections by opportunistic microorganisms such as mucormycosis. Early diagnosis and adequate treatment are essential due to their intrinsic difficulty and the high mortality rate of these cases.