RESUMEN
We investigated the effect of social networking [SN] on academic achievement of dental students at Jazan University, Saudi Arabia. A self-administered questionnaire was distributed during the 2015/16 academic year to all dental students and data were analysed by SPSS version 21. There were 348 participants [70% response rate] and 53% were male. Fifty-one percent of participants reported that they studied just before examinations, and 51% scored 3.5-4.5 Grade Point Average [GPA] in the last semester. Up to 98% of the participants reported using their smartphones/computers for SN, with 93% doing so on a daily basis, and 66% reported SN during lectures, laboratories and clinics. Fifty-seven percent thought that SN affected their study negatively, and 65% thought that their GPA would improve if they stopped or reduced SN. Students who spent more hours each day on SN had lower GPA scores. SN negatively affected the academic achievement of dental students. Further evaluation and tailored educational programmes are needed to increase students' awareness about the negative effects of SN