This study tested 43 nursing, pharmacy, and medical personnel for their accuracy in calculating drug doses for newborn infants. Based on a series of examples, study participants scored well if a high percentage of problems were answered correctly. Discussion includes comparison of performance across disciplines, the impact of experience on higher test scores, and suggestions for reduction of potential adverse events in drug administration. The authors conclude that, although pharmacists scored higher than physicians who scored higher than nurses, the rate of error requires system changes, such as computerized programs, to improve safety of this process.