The ascites retention as a complication after ventriculo-peritoneal shunting (V-P shunt) is very rare. In this paper, a case of central nervous cryptococcosis giving rise to ascites after a V-P shunt is presented. A 45-year-old female was referred to Prefectural Gifu Hospital complaining of nausea and disturbance of recent memory. She had no remarkable medical history. CT scan films on admission showed enlarged ventricles except for the fourth ventricle, indicating an obstructed hydrocephalus. Lumbar cerebrospinal fluid (CSF) examinations revealed an increase in cell counts (mostly lymphocytes) and protein content, and positive Pandy and Nonne-Apelt reactions. Based on this information, it was tentatively suggested that she had a certain infection in the central nervous system such as mycosis or tuberculosis etc. Continuous ventricular drainage was performed for about three weeks. During this period, several lumbar and ventricular CSF cultures were negative. Therefore, a V-P shunt operation was performed. However, about seven weeks after the V-P shunt, she developed abdominal distention without any peritoneal signs. Abdominal CT scan films showed an abnormal ascites retention. Laboratory tests revealed positive CRP and increased ESR values. Again, it was suggested that she had not only a central nervous but also a peritoneal infection giving rise to ascites. From samples of ventricular CSF and ascites, cryptococcus neoformans was cultured. The lumbar CSF revealed positive latex agglutination titer for cryptococcal antigen, although the culture was negative. The ascites examination revealed an increase in cell counts (mostly lymphocytes) and protein content, and positive Rivalta and Runneberg reactions.(ABSTRACT TRUNCATED AT 250 WORDS)