Primary plasma cell leukemia is a rare variant of malignant monoclonal gammapathies with de novo presentation in the leukemic phase. Only few series enrolling more than 20 patients have been reported in the literature. The authors deal with a patient who had a fulminant presentation of primary plasma cell leukemia with fatal outcome. Diagnosis of primary plasma cell leukemia was established based on Kyle's criteria, which include an absolute plasma cell count greater than 2 x 10(9)/L or a relative plasma cell number comprising greater than 20% of peripheral blood cells. The patient died within three days of diagnosis because of Streptococcus pneumoniae septic shock and multiple organ failure. This case report is worth of note due to the rarity of primary plasma cell leukemia and also because fulminant presentation is not commonly recognized among patients with malignant gammapathies.