This study aims to examine the critical success factors, namely perceived interactivity, advertising avoidance, credibility and privacy, influencing the attitudes of Millennials toward Facebook advertising. In addition, this study also explores the differences in demographic profile groups toward Millennials' attitudes on Facebook advertising. A total of 257 undergraduate students at Universiti Teknologi Malaysia (UTM) using convenience sampling was selected for the data analysis. Numerous tests including normality test, reliability test, t-test, Anova and multiple regression analysis are used to examine the relationships between perceived interactivity, advertising avoidance, credibility, privacy level and attitude towards advertising in Facebook. The data collected from respondents was analysed using Software Package used for Statistical Analysis (SPSS). The factors including perceived interactivity, credibility, and privacy are proved to have relationships with attitude toward Facebook advertisement. Perceived interactivity is the best predictor to estimate Millennials' attitudes toward advertisement on Facebook. Besides, gender and daily frequency of using Facebook are significantly different toward Millennials' attitudes on Facebook advertising. In contrast, race, nationality and year of study showed no significant difference in influencing Millennials' attitudes on Facebook advertising. The findings might provide an indicator for companies to measure the effectiveness of their advertising on Facebook.