Facebook is a ubiquitous platform for self-disclosure; however, norms associated with online and offline disclosure appear to differ. The present study investigated whether people's disposition to disclose and comfort with others' disclosures of negatively-valenced content differs online and offline. Additionally, psychological predictors of offline and online disclosure were explored. Results revealed that offline disclosure of negatively-valenced personal information is preferred to online disclosure and that comfort with others' disclosure of such information is greater offline than online. As information becomes more sensitive, the likelihood of sharing this information online decreases; similarly, the degree of comfort with others' online disclosure of such information decreases. Agreeableness was positively correlated with reactions to others' online posts. Agreeableness, openness, self-esteem and emotional stability were positively correlated with comfort with others' offline disclosures. Tendency to disclose online was higher for those with low emotional stability and low openness (but only for some scenarios). Age effects were most prominent with respect to the information shared and comfort with others' disclosures, but across age groups there was a preference for offline, rather than online, sharing. Collectively, the results reveal that individual differences are weaker predictors of online disclosure than the nature of information disclosed.