The research aimed to investigate undergraduate students' nomophobic behavior; and its relationship with certain demographics and certain mobile phone activities. Moreover, it was explored whether there were any significant differences among the four sub-dimensions of nomophobia: "not being able to communicate," "losing connectedness," "not being able to access information", and "giving up convenience." A correlational research design was employed with a sample of 146 undergraduate students from four different faculties of a Turkish state university by using convenience sampling method. The Turkish Nomophobia Questionnaire was used for data collection. By conducting One-Way Repeated ANOVA, a significant difference between the mean scores of four dimensions was found. While the students' scores on the fear of "losing connectedness" were significantly lower than the other three factors, the fear of "not being able to access information" had the highest mean scores. There was no difference between the factors "not being able to access information" and "not being able to communicate." Furthermore, the Pearson' Product Moment correlation was performed; its results indicated that there was a weak, yet significant, correlation between gender and the sub-dimension of "not being able to communicate." There was also a weak positive correlation between the Internet browsing and the four dimensions of nomophobia. The study also found a weak positive correlation between learning/education and the level of "not being able to access information."