Fetal blood sampling has been employed in the diagnosis of fetal distress at the Columbia-Presbyterian Medical Center since November, 1965. A total of 1,200 samples have been obtained from 678 infants with 6 neonatal complications. Scalp abscesses developed in 3 infants and 3 sustained substantial hemorrhages from scalp incisions. The 6 complications are reported in detail and the literature is reviewed. It is concluded that certain factors, such as vacuum extractions, sampling in breech presentations, neonatal coagulation defects, and maternal infection, may increase the incidence of complications. Strict aseptic technique in the sampling procedure is recommended. The obstetrician is cautioned about the potential hazard of making multiple incisions and is urged to watch for scalp hemorrhage or vaginal bleeding following incisions. The pediatrician is advised to perform coagulation studies on infants who hemorrhage significantly from scalp incisions.