Malignant ascites is a common symptom in patients with peritoneal cancer. Current assumption is that an increased vascular permeability and obstruction of lymphatic channels lead to the accumulation of fluid in the abdominal cavity. This case report describes a severely symptomatic patient with malignant ascites. The previously healthy 73-year-old male was presented with abdominal distention causing respiratory distress. Computed tomography revealed large amounts of ascites, a recto-sigmoidal mass with locoregional lymphadenopathy and an omental cake. Biopsy taken during colonoscopy revealed an adenocarcinoma of the colon with signet cell differentiation. A widespread peritoneal carcinomatosis was found during a diagnostic laparoscopy. The extent of peritoneal disease rendered the patient not suitable for cytoreductive surgery with curative intent. The ascites proved to be refractory to ultrasound-guided paracentesis; thus, a decision was made to perform palliative hyperthermic intraperitoneal chemotherapy without cytoreductive surgery. Consequently, ascites production stopped, and the respiratory distress was relieved thereafter. The postoperative recovery was uneventful. Ascites recurred eight months later, and a second hyperthermic intraperitoneal chemotherapy procedure was performed. The patient was still alive at the time of writing, 16 mo after the initial diagnosis.