Blood gas measurements performed at the central laboratory and at a satellite laboratory of Brigham and Women's Hospital were studied to determine the differences in quality, turnaround time (TAT), and cost. The quality in both laboratories, as determined by results on proficiency and quality control samples, satisfactorily met current standards for patient care. The central laboratory receives specimens for blood gas measurements through a pneumatic tube system and broadcasts results to computer terminals at the originating site, with a mean TAT of 6 minutes. The satellite laboratory, which is within the neonatal intensive care unit that it serves, has a mean TAT of 4.5 minutes. The difference is attributable to transit time in the pneumatic tube and accessioning time in the central laboratory. The total cost per reportable result was substantially higher for the satellite laboratory than for the central laboratory. The minor difference in TAT can be considered in a cost-benefit analysis that weighs medical utility criteria against cost.