Drawing from the Conservation of Resources (COR) theory, this study examines the moderating effect of social exclusion on the relationship between insomnia and cyberloafing by conducting two studies. Study 1 was based on a lab experimental design that measured cyberloafing objectively. Results of Study 1 showed that sleep deprived participants who were lonely engaged in higher levels of cyberloafing compared to those who were not lonely. As experiments tend to lack external validity, we will conduct a second study to enhance the generalizability of our findings. Study 2 will be conducted using a survey of working adult sample. Implications of our findings are discussed.