This study investigated the use of social media by undergraduates in South-West Nigeria using Bowen and Olabisi Onabanjo universities as a case study. A descriptive research design method was employed for this study, while the population consisted of undergraduate students from thirteen faculties at OOU and seven faculties at BU who are offering undergraduate programs with total population of 15, 291. A multi stage sampling method was adopted to select 10% of 3465, giving a sample size of 348. A questionnaire was the major instrument used for data gathering and the data obtained was analyzed through SPSS. The study found that the undergraduates are aware of the social media tools as majority from both institutions frequently use Facebook, WhatsApp, on daily basis and Blog, YouTube, Flickr were used on weekly basis. Also, constraints such as cyber-bullying, lack of privacy, time wasting, addiction, being distracted were some of the highlighted problems encountered by both institutions in the use of social media tools for educational activities. Conclusion and recommendations were made based on the findings.