Objective: 1) To access the impact of Facebook on the health and well-being of users. 2) To study the behavior of Facebook users. 3) To determine the percentage of Facebook users among university students.

Material and Method: This was a cross-sectional study conducted at Prince of Songkla University, Hat Yai Campus, from August to September 2012. A self-administered questionnaire was used consisting of demographic characteristics, behaviors, and the consequences of using Facebook. Data were analyzed using descriptive statistics presented in the form of frequency and percentage. Logistic regression was used to determine factors associated with Facebook addiction.

Results: Four hundred twenty students were sampled, 197 were male (46.9%) and 223 were female (53.1%). Average age was 20.3 years old. The results showed that 416 students (99.0%) had used Facebook within the previous 6 months. The average duration of use was about 3 hours per day (standard deviation; S.D.=2.6). There were 187 students (45.0%) who perceived that they were addicted to Facebook, while 115 students (27.6%) were addicted according to our criteria. Among these, 50 students (43.5%) were male and 65 students (56.5%) were female. Facebook addiction had a statistically significant association with student course of study (p=0.024). Students in the sciences and health sciences were 2 times likely to be addicted to Facebook compared to students in the social sciences. Moreover, Facebook addiction was also associated with a higher likelihood of having fewer interactions with people in real life, conflict with other Facebook user, lower performance, lack of sleep or relaxation time, game addiction on Facebook, decreased concentration, feelings of low self-esteem, concern with news on Facebook, and feeling scared or threatened.

Conclusion: Ninety-nine percent of the students had used Facebook. Twenty-seven point six percent of the students were addicted to Facebook and this was associated with a negative impact on the health and welfare of students.