Seven patients received intraperitoneal chromic phosphate (32P) suspension in a 3-ml bolus with a saline flush, and another ten patients were given the suspension in a 500-ml infusion of normal saline. During the first six hours after administration, most 32P activity redistributed to the gravity-dependent portion of the peritoneal cavity. From 24 hours up to seven weeks after administration, activity distributions were fixed. Dispersions were heterogeneous in every patient, but the most marked examples of localized activity occurred in patients who had received bolus injections. We concluded that large-volume infusions and frequent changes in patient position for several hours following the infusion, contribute to improved dispersion of 32P suspension.