Summary Background The current two-stage study focused on work integration and quality of life of patients in an acute psychiatric day care unit. There is evidence that a longer absence from work due to illness negatively affects job retention, life satisfaction and clinical prognosis. Furthermore, there are individual supportive methods that proved to be effective in work integration. We therefore developed a specific group program Fit for Work and Life (FWL) for patients in an acute psychiatric day care unit focusing on work integration in the first labor market (in contrast to work in institutions for people with disabilities/second labor market). Methods Between 2018 and 2020, 62 patients (intervention group; IG) were enrolled in an 8‑week prospective job integration program and compared to 74 patients (control group; CG) who received treatment as usual (partly retrospective survey). Patients of both groups held a job when entering treatment. Main outcome was defined as their working status 4 weeks after the end of treatment as well as self-reported life satisfaction. Results At the end of treatment (i.e. the week prior to discharge), the IG participants reported higher overall life satisfaction as well as higher health-, self- and living condition-related satisfaction than controls. Functional and clinical improvement during treatment was linked to subsequently returning to work. Functional improvement was further linked to higher life satisfaction. Mediational analysis revealed an indirect path from functional improvement on life satisfaction via working status, i.e. the higher functional improvement during treatment, the higher the chance of successfully returning to work, which in turn increased life satisfaction. Conclusion Our findings suggest that programs such as FWL are useful interventions for employed patients to improve reintegration into work and life and to help to increase life satisfaction.