ObjectivesTo determine learning strategies, study habits, and online social networking use of undergraduates at an Irish medical school, and their relationship with academic performance. MethodsA cross-sectional study was conducted in Year 2 and final year undergraduate-entry and graduate-entry students at an Irish medical school. Data about participants’ demographics and educational background, study habits (including time management), and use of online media was collected using a self-report questionnaire. Participants’ learning strategies were measured using the 18-item Approaches to Learning and Studying Inventory (ALSI). Year score percentage was the measure of academic achievement. The association between demographic/educational factors, learning strategies, study habits, and academic achievement was statistically analysed using regression analysis.  ResultsForty-two percent of students were included in this analysis (n=376). A last-minute “cramming” time management study strategy was associated with increased use of online social networks. Learning strategies differed between undergraduate- and graduate-entrants, with the latter less likely to adopt a ‘surface approach’ and more likely adopt a ‘study monitoring’ approach. Year score percentage was positively correlated with the ‘effort management/organised studying’ learning style. Poorer academic performance was associated with a poor time management approach to studying (“cramming”) and increased use of the ‘surface learning’ strategy.                   ConclusionsOur study demonstrates that effort management and organised studying should be promoted, and surface learning discouraged, as part of any effort to optimise academic performance in medical school. Excessive use of social networking contributes to poor study habits, which are associated with reduced academic achievement.