In this study, it was aimed to examine the association between gender, personality traits and Twitter addiction (TA) among undergraduates. Study group consisted of 365 undergraduate students who are enrolled at the state university in western region of Black sea. Big Five Inventory, TA Scale and personal information form were used for data collection. In order to analyze the data, descriptive statistics, t test, Pearson's correlation and multiple regression analyses were utilized. As a result of the study, it was found that while 37.5% of the participants were mildly addicted to Twitter, 14.5% of them were addicted moderately. Another finding suggested that addiction levels of the male students were significantly higher than females. Results also indicated that while gender was positive predictor of TA, agreeableness, conscientiousness and extraversion were significantly negatively predicting the TA levels of the Turkish undergraduates.