The study attempts to determine whether or not Facebook is an environment suiting the Community of Inquiry Framework by investigating the cognitive, social, and teaching presence perceptions of students in Facebook groups and to examine the impact of group size on the CoI model. Additionally, whether or not these three types of presences predicted academic success and motivation were investigated. The data were analyzed through logistic regression analysis, independent samples t-test and the Pearson correlation coefficient. The study was conducted in a blended course, where Facebook was utilized for online discussions. The study revealed that the relation between cognitive, social, and teaching presences was significant and at a high-level. The high correlation determined among the social, cognitive, and teaching presence perceptions of students in learning communities created on Facebook leads to the consideration that Facebook is a suitable online environment for the COI framework. It is understandable, that all presence perceptions are higher in smaller groups when group impacts are investigated. Other conclusions derived from the study are that academic success was only predicted by cognitive presence and motivation was predicted by both cognitive and teaching presences.