This paper explores the role of self-management of chronic illness at work, as a predictor for self-disclosure. The study reports findings from a survey sent to all staff at a UK university, of which 610 employees reported managing a chronic illness: arthritis, musculoskeletal pain, diabetes, asthma, migraine, heart disease, irritable bowel syndrome and depression. The study found that discrete self-management factors predicted different levels of disclosure: partial self-disclosure (employees informing line managers about the presence of a chronic illness) and full self-disclosure (employees informing line managers how that chronic illness affected them at work). For partial disclosure, a greater reported experience of chronic illness by employees was positively associated with self-disclosure. For full-disclosure, employees were more likely to report disclosure to line managers if they had already disclosed to colleagues, and if they perceived receiving support from their line managers in relation to their chronic illness as important. Except for academics who were least likely to disclose, occupational groups did not emerge as significant predictors for either partial or full disclosure. Except for diabetes, chronic illness itself was not a significant predictor or barrier to self-disclosure. Our findings suggest that chronically ill employees adopt a disclosure strategy specifically related to different self-management needs of chronic illness at work.