Today, consumers are undoubtedly surrounded by various types of advertisements. Companies have resorted to various ways to succeed and influence the minds of their target audiences. Approving products and services by celebrities as the endorsers to the community is one of the most effective and costly methods that companies have used to make their brands better known and reminded than ever before. The main purpose of this study is to investigate the effect of celebrity endorsements in advertising on the image of advertised brand. In this research, seven aspects of the effectiveness of celebrity endorsements, including expertise, attractiveness, popularity, familiarity, appropriateness, similarity, and trustworthiness, were analyzed and evaluated as independent variables and their impacts on brand image as a dependent variable. In terms of purpose, this research is applied and with regard to data collection, it is considered descriptive-survey method which is of correlation type. The statistical population of the study consisted of all consumers of cosmetic products in Iran. Among this unlimited society, 385 individuals were selected online through social networks with available sampling method. The data was collected using questionnaire. In order to test the research hypothesis, modeling structural equations using Smart PLS software (partial least squares) has been used. The results of the study showed that the effect of some features of Celebrity Endorsements effectiveness, including attractiveness, popularity and similarity on the brand image were confirmed. But, some other features such as expertise, trustworthiness, familiarity and appropriateness, on brand image was not confirmed in this study.