Background: People with multiple sclerosis (PwMS) are known to use a wide range of medical and non-medical treatments. This study aims at investigating the use of self-care activities within this patient group. Material and Methods: The study follows a descriptive cross-sectional design based on an online survey among members of the Danish Multiple Sclerosis Society's permanent respondent panel. Results: The results of the study indicate that the respondents carry out a wide variety of self-care activities. These activities comprise conventional activities as well as complementary and alternative medicine (CAM)-based activities. The self-care activities are mainly kept up for non-specific and preventive purposes, with primarily personal or non-specific issues as the primary source of inspiration. Comparative analyses indicate that respondents with a low level of self-care more often are men, belong to the young age group and have a low level of education, a low level of self-assessed state of health, a low level of self-assessed quality of life (QoL), and an unknown subdiagnosis. Respondents with a high level of self-care are more often women and have a high level of self-assessed QoL. Conclusions: A wide variety of self-care activities are carried out by PwMS, comprising conventional as well as CAM-based activities. The purposes of such activities are manifold, but they are mainly of non-specific and preventive nature. Differences in background characteristics exist between groups of low and high levels of self-care.