Research has shown that the willingness to interact with colleagues in offline contexts mostly depends on morality traits. However, little is known about how social judgments of traits can influence online intentions to interact with colleagues. Specifically, we investigated the effects of colleagues' morality, sociability, and competence traits on employees' boundary management on Facebook. An experiment (N = 289) was conducted using a (morality: high vs low) by 2 (sociability: high vs low) by 2 (competence: high vs low) design. Results revealed that employees' preference to separate (vs. integrate) professional and private contacts on Facebook was determined by both morality and sociability traits, whereas no effects of competence traits were found.