Importance: Premenstrual disorders (PMDs) are prevalent and significantly impair women's quality of life. Yet, the long-term impact on work capacity is not well understood. Objective: To prospectively examine the association between PMDs and work incapacity, including sick leave and unemployment. Setting, Design and Participants: A prospective cohort study of 15,857 women aged 15-60 years and employed at baseline in the LifeGene Study with linkage to population and health registers in Sweden. Exposure: PMDs were identified via register-based clinical diagnoses and symptom questionnaires. Main Outcomes and Measures: We extracted information on sick leave and unemployment status from national registers. We used Poisson regression to estimate incidence rate ratios (IRRs) of sick leave and unemployment comparing women with PMDs to those without. Results: In total, 2,585 (16.30%) women (mean age 32.52 years) reported symptom burden indicative of probable a PMD. With a median follow-up of 9.17 years, 6,741 (42.51%) and 1,485 (9.36%) women were exposed to at least one sick leave and unemployment during follow-up, respectively. Compared to women without PMDs, those with PMDs had 40% and 27% higher risks of sick leave (fully adjusted-IRR 1.40, 95% CI 1.31-1.49) and unemployment (IRR 1.27, 95% CI 1.10-1.46), respectively. The association was particularly stronger for long-term sick leave (≥ 90 days) (IRR 1.69, 95% CI 1.50-1.91), and sick leave due to depression (IRR 1.41, 95% CI 1.27-1.56). In addition, comparable associations for sick leave and unemployment were yielded, when comparing women with and without a history of depression/anxiety. Conclusions: Employed women with PMDs are at increased risk of sick leave and unemployment, underscoring the potential long-term health and socioeconomic consequences of this prevalent condition. Improved clinical management of comorbidities and workplace policies are needed to support women affected by PMDs.