The study uses 15 waves of the British Household Panel Survey and the General Health Questionnaire to investigate changes in mental distress over several years surrounding transitions both into and out of marital partnerships (marriages and cohabitations) using fixed effects models. Entering marital partnerships is associated with reduced distress in separated or divorced individuals but not with those not previously married. Partnership dissolution is associated with very high levels of distress, but most people experience levels of distress a few years after leaving a partnership similar to that of a few years before leaving. These results vary, however, between married and cohabiting individuals, between fathers and mothers, and between age and gender groups.