Catheter dysfunction is a common complication with ventriculoperitoneal shunts. Apart from infection, obstruction, and leakage, migration of the shunt tip may cause particular problems. Pleural effusion is easily classified as a shunt complication if a transdiaphragmatic migration of a shunt can be demonstrated. If, however, the tip of the shunt is found adjacent to the diaphragm, it is difficult to decide if the effusion is caused by the ventriculoperitoneal shunt. Different diagnostic methods can be used in this situation. Below we report a case of pleural effusion-without shunt migration-which was revealed to be a shunt complication by quantifying beta-trace protein in the effusion.