Although prenatal genetic amniocentesis is an accepted procedure for certain high-risk pregnancies, there is no standard approach to prenatal counseling, timing of counseling, materials used and location of the procedure. This survey of 126 genetics centers offering prenatal genetic amniocentesis reviewed aspects of 48,502 counseling events and a total of 61,174 samples processed in 1982. Eighty-three percent of the samples were obtained after counseling at the centers. Of the patients counseled, 88.5% chose amniocentesis, but the utilization rates varied widely between the centers. The choice of amniocentesis varied measurably with the educational materials used but not with the center size. Educational materials, written or audiovisual, were used by genetics centers in counseling 82% of the patients. There was a wide variation in center size, counseling methods used, the timing and use of counseling, and patient responses in the survey population.