The aim of this exploratory study was to test the applicability of a model derived from the Theory of Planned Behavior on self-management. In this model social support from the partner, attitude and self-efficacy are determinants of intention, and intention and self-efficacy are determinants of self-management. We tested the model on rheumatoid arthritis patients who have a partner, using regression analyses and structural equation models. Partner support and attitude partly explained the variance in intention. Intention in turn partly explained the variance in self-management. Self-efficacy showed a tendency to positively affect intention and self-management. The present study provided moderate support for the use of the constructs and ideas derived from the Theory of Planned Behavior-attitude, social support, self-efficacy, and intention-in predicting and explaining self-management.