Objectives: Depression is associated with lowered work functioning, including absence, productivity impairment at work, and decreased job retention. Although high-quality depression treatment provided in clinical trials has been found to reduce symptoms and improve work function, the effectiveness of routine treatment for depression in primary care has received less attention. Study Design: This prospective cohort study investigated the relationship between improvements in both depression symptoms and productivity in outpatients from 77 clinics in Minnesota following routine depression treatment. Methods: Data were obtained from patients receiving usual care for depression prior to initiation of a statewide quality improvement collaborative called DIAMOND (Depression Improvement Across Minnesota: Offering a New Direction). Patients started on antidepressants were surveyed on depression symptom severity (Patient Health Questionnaire [PHQ-9]), productivity loss (Work Productivity and Activity Impairment questionnaire [WPAI]), health status, and demographics. Data were collected again 6 months later to assess changes in depression symptoms and productivity. Results: Data from 432 employed patients with complete baseline and outcome data showed significant reductions in depression symptoms and increases in productivity (P <.0001) over 6 months. Greater improvements in productivity at 6 months were associated with greater improvement in depression symptoms as well as with greater depression severity (P <.0001) and poorer productivity (P <.0001) at baseline. Conclusions: This study demonstrated a significant relationship between improvement in depression symptoms and improvements in productivity following routine primary care depression treatment. These findings underscore the benefit of depression care to improve work outcomes and to yield a potential return on healthcare investment to employers.