Ascites is rare in patients with multiple myeloma (MM). It may be due to diverse mechanisms, most frequently because of an increased permeability of the peritoneum or because of portal hypertension due to liver infiltration. Myelomatous ascites occurs more frequently in patients having Ig-G or Ig-A paraprotein and their prognosis is poor. It is submitted the case of a female patient aged 50 years with IgA-kappa MM, who evolved with cardiac failure (CF), plasma cells leukemia and ascites of mixed cause, because of peritoneal infiltrate of myelomatous cells, hepatic compromise and CF. A review of the different causes of ascites in patients with MM is performed. There are also summarized all myelomatous ascites cases published in the literature. Our report presents the first case of myelomatous ascites in a patient with plasma cells leukemia.