Corticosteroids are often misused as whitening cosmetic. Therefore, it is necessary to educate the abuser. Educator need to know the level of abuser’s knowledge, attitude, and practice (KAP) so that efficient educational outcomes. The purpose of this study to identify KAP’s level of cosmetic users. The study used a cross-sectional design and questionnaires as instruments. The population is female of Medical Students UMY. These samples included 65 people were divided into 3 groups, 32 people as a group A (abuser), 15 people as a group B (accidental abuser), and 18 people as a group C (non abuser) . Statistical tests show there are significant differences in knowledge (p = 0.044) and practice (p = 0.000). Post Hoc test show there are significant differences knowledge in group A with C (p = 0.021), in practice there are groups A and B (p = 0.000), A with C (p = 0.015), and B with C (p = 0.001). The concusion are knowledge 44.6% generaly has good category, over all 64.6% attitude has good categories, generaly practice has 33.8% in bad category. In the three groups of respondents corelations of KAP are uncertain.