The clinical ABCD criteria are still recommended to both physicians and laymen when checking moles. The aim of this study was to determine the level of interrater reliability and therefore objectivity in rating for one of these criteria, namely border irregularity. Five professors, five residents, five nurses, and 10 students rated a set of 54 clinical images of pigmented skin lesions for border irregularity. After a descriptive presentation, rating was again carried out on another set of 54 images. In all groups, the agreement was moderate or substantial before the presentation and increased after the presentation. An almost perfect agreement was achieved by the professors after the presentation. Although both experience and receiving information could increase the level of interrater reliability, the disagreement was usually sufficient to suggest subjectivity in rating for border irregularity.