One hundred sixty-one professionals and 97 undergraduates were asked to (a) prioritize 12 hypothetical CPS cases on the basis of sexual behaviors displayed by children, and (b) estimate the probability of abuse in a single case involving a child who had displayed sexual behavior and came from a population with a known base rate of abuse. When asked to prioritize the 12 cases as "high," "medium," or "low" on the basis of sexual behaviors, professionals were more accurate than students. However, when asked to estimate the probability of abuse in the single case, both professionals and students failed to incorporate base rate information into their decisions. As a result, both groups misestimated the probability of abuse under some circumstances. Professionals' performance on both judgment tasks was unrelated to level of experience with sexual abuse cases.