Objective: The objective of this study was to determine what makes men and women with musculoskeletal complaints decide to call in sick for work. Methods: Qualitative, face-to-face interviews were used with employees (16 men and 14 women) who had called in sick due to a musculoskeletal complaint and who expected to be absent from work for at least 2 weeks on sick leave. Results: The participants fell into the following two main groups: those who were off sick because of a diagnosed medical condition, such as a fracture, and those who were off sick because of an unidentifiable complaint, such as low-back pain. Employees in the former group called in sick because they were in the hospital or because they reckoned that their condition was too serious to warrant a continuation of work. Employees in the latter group felt hesitant and insecure and found it hard to judge whether absenteeism was justified. They decided either to "play it safe" and stay off work to prevent the complaints from worsening or to seek advice from medical professionals. Their advice did not include explicit instructions to stay at home, but were usually interpreted as such. Finally, women, but not men, were likely to call in sick if they felt that their home situation was being negatively affected by attempts to keep working while suffering physical complaints. Conclusions: The decision to call in sick is not taken lightly. Employees with nonspecific disorders base their decision on several factors, including advice from medical professionals. A factor found only among women was work-home interference. This work is licensed under a Creative Commons Attribution 4.0 International License.