Intravenous admixtures containing potassium collected from three hospital pharmacies were analyzed for compounding accuracy, sterility and pyrogenicity. The study was performed in two stages. During stage I, pharmacists and technicians were not informed of the study, but during stage II they were informed. In each stage 10 samples were collected from each person in the two personnel groups, analyzed and the results compared between the two personnel groups and the two stages. Results of the study showed that without monitoring (stage I) pharmacists had a higher mean percent error and contamination level than technicians. With monitoring, however, pharmacists showed a lower mean percent error and contamination level than technicians. Both personnel groups showed a decline in their mean percent error in the second stage, but there were still 83 (39.5%) errors in compounding accuracy greater than +/- 6%. No positive results with the Limulus test for pyrogens were obtained. It is recommended that a planned program of quality control be instituted for the preparation of i.v. admixtures by both pharmacists and technicians.