One hundred and ninety surgically documented cases of Meckel's diverticulum encountered at the Mayo Clinic during a 51-year period, 1920 through 1971, are reviewed. In 39 patients, the diverticulum was left undisturbed. In 51 patients, the diverticulum was the primary surgical disease, and, in 100 patients, the diverticulum was removed incidentally. The clinical features are presented as well as the surgical considerations. Meckel's diverticulum is a relatively frequent development anomaly with eccentric manifestations, and its surgical management has intrigued physicians for over 350 years. Dr. Charles W. Mayo stated, "Meckel's diverticulum is frequently suspected, often looked for, and seldom found."