This study examined the use of social network for knowledge sharing among undergraduates students using Ambrose Alli University Ekpoma Edo State as a case study. The field survey research design was used in this study. The instrument used for data collection was questionnaire. The population of this study consist of all undergraduate library and information science students of Ambrose Alli University Ekpoma (AAU). However a sample size of one hundred and fifty (150) undergraduate students in library and information science in one university in Edo State was used. A total of one hundred and thirty two (132) copies of the questionnaire were retrieved and analyzed with simple table percentage, mean and standard deviation. It was found that students share knowledge on entertainment, about exam, lectures and timetable. It was also found that Students share knowledge to learn from each other and to maintain reciprocity in relationship. It was also found that students use Whatsap, Facebook, YouTube and BBM messenger. It was also found that poor internet connection, delay in response from the other party, tendency to be distracted online and epileptic power supply hinder students in using social network. The study recommended that: students who are heavy users, should moderate the use of the sites to avoid addiction and create a balance between their offline and online lives while using the sites and tertiary Institutions should organize a seminar to enlighten students on the not too-good aspects of using social networking sites as media of interaction.