Objectives: We explored whether changes in the perceived health of homeless people after entering the social relief system (SRS) in The Netherlands were predicted by housing, income, hours of work, social support, unmet care needs, arrests, physical and mental health, substance use, and experiences of autonomy, competence and relatedness, in addition to perceived health at baseline, demographics, suspected intellectual disability, the duration of homelessness and the company of children in the shelter facility. Methods: A hierarchical regression analysis was used to explore the significant predictors of the perceived health of 344 homeless persons 18 months after entering the social relief system. Results: A decrease in psychological distress and an increase in hours of (paid/voluntary) work as well as competence predicted a better perceived health. Conclusions: Perceived health is not only influenced by objective circumstances related to work and mental health, but also self-determination, as shown by the influence of competence. Services should aim to reduce psychological distress of homeless people, support them in increasing their working hours and focus on strengthening their competence.