Eight new cases of Meckel syndrome, two of them occurring in the same family, are presented. Occipital encephalocele of varying extent, multicystic renal dysplasia not associated with urinary tract obstruction, and postaxial hexadactyly comprise the three basic features of this lethal syndrome with autosomal recessive inheritance. From our observations it appears that congenital hepatic fibrosis, abnormal external genitalia in male infants and a malformed tongue with lipomatous excrescences are also frequently occurring anomalies with important diagnostic value. The statement that the majority of cases of Meckel syndrome can be detected prenatally is further supported by two cases in the present series. The incidence of this syndrome may be much higher than previously thought.