Current research aimed to investigate the structural relationships among knowledge sharing behavior, adoption of Facebook and virtual loneliness behavior. The dataset of this study were gathered from Knowledge Sharing Behaviors (KSB) Scale, Facebook Adoption (FA) Scale and Virtual Environment Loneliness (VEL) Scale. Structural equation modelling was used to test the research hypotheses. The structural relationships among KSB, FA and VEL of the virtual community members were examined. It was found that there were moderate and significant relationships in a positive direction among KSB, FA and VEL. The structural model indicated that the increase in the FA and decrease in the VEL levels of the community members improved KSB as well. It was seen that the highest factor load value in KSB scale originated from FA scale. Today, Facebook is one of the most popular social networking sites (SNS) to create virtual communities. In addition, the impact of adoption of Facebook by community members and the feeling of virtual loneliness arising as a result of using Facebook were examined.