OBJECTIVE: To report a case of Ludwig's angina in a patient later diagnosed with postpartum acute myeloid leukemia treated at the Hospital Regional of Presidente Prudente in the period from February 25th to March 1st of 2012. CASE REPORT: EVS, 23 years old, female, born and resident of Oswaldo Cruz - SP, primigravida, 30th day of puerperal of normal term pregnancy, preeclampsia episode, presented with pain in throat and odynophagia of moderate intensity. Outpatients treated with anti-inflammatory and azithromycin 500mg/day, with a significant worsening of the situation after two days of treatment. She was referred to the HRPP with suspected bilateral deep cervical abscess. It was reviewed by surgical team of head and neck, and Ludwig's Angina diagnosed by abscess affect regions submandibular, sub mental and sublingual. After laboratory tests, we observed marked pancytopeny and alterations in coagulation. After compensation, laboratory, performed neck incision for abscess drainage and tracheotomy. The patient was in intensive care with broad-spectrum antibiotic (meropenem, vancomycin). The framework developed unfavorably, being evaluated by a hematologist, who, after laboratory tests, was diagnosed with acute myeloid leukemia, justifying the lush course of infection. The patient developed sepsis and died days March 01st of 2012. CONCLUSION: Ludwig's Angina is a severe infectious-inflammatory process, which treatment is aggressive, especially when it evolves rapidly, requiring further investigation to determine the basic conditions to justify such as immunosuppressive diseases.