Out of 528 children with Crohn's disease in a Multicenter Paediatric Crohn's Disease Study Group, 37 cases had epithelioid granulomas but did not fulfill defined radiographic criteria of the disease. Follow-up studies including clinical, biochemical, radiological, endoscopic, and histological investigations were done in these patients. Initially, all patients showed clinical symptoms and 27 of them had biochemical signs of chronic inflammation. After a mean follow-up of 3 years, all 37 children treated for Crohn's disease got a complete upper gastrointestinal series with small bowel followthrough and 8 children in addition had barium enemas. Colonoscopies were done in 23 patients. Radiographic examination revealed Crohn's disease in 14 and endoscopy additionally confirmed Crohn's disease in 8 further cases. One child was diagnosed as having chronic granulomatous disease. Thirteen children still remained unclassified after these follow-up studies including radiographs and endoscopy. An interval of 3 years may in some cases be too short to express the complete radiographic pattern of Crohn's disease. Our studies demonstrate that in addition to initial radiological, endoscopic, and histological investigations, a thorough follow-up is necessary in early diagnosed patients. In these children, epithelioid granulomas are of high diagnostic validity preceding radiological changes of Crohn's disease often for years.