Percutaneous endoscopic gastrostomy (PEG) is frequently used for long-term enteral nutrition or gastrointestinal decompression in both adults and children. The rare complication of a cologastric fistula following PEG has been seen recently in two pediatric patients. One fistula did not close after removal of the gastrostomy tube. A mechanism for the occurrence of this complication in these two children is proposed and technical points are emphasized to prevent this complication.