Introduction: High quality of early stroke care is essential for optimizing the chance of a good patient outcome. The quality of care may be monitored by process performance measures (PPMs) and previous studies have found an association between fulfilment of PPMs and short-term mortality. However, the association with long-term mortality remains to be determined. We aimed to evaluate the association between fulfilment of PPMs and long-term mortality for patients with acute stroke in Denmark. Patients and methods: We used data from Danish health care registers between 2008 and 2020 to identify all patients admitted with incident stroke (haemorrhagic (ICH) or ischaemic stroke). The quality of early stroke care was assessed using 10 PPMs. Mortality was compared using Cox proportional hazard ratios, risk ratios computed using Poisson regression, and standardized relative survival. Results: We included 102,742 patients; 9804 cases of ICH, 88,591 cases of ischaemic stroke, and 4347 cases of unspecified strokes. The cumulative 10-year mortality risk was 56.8%. Fulfilment of the individual PPMs was associated with adjusted hazard rate ratios of death between 0.76 and 0.96. Patients with 100% fulfilment of all PPMs had a lower 10-year post-stroke mortality (adjusted risk ratio 0.90) compared to the patients with 0%–49% fulfilment and a standardized relative survival of 81.3%, compared to the general population. Conclusion: High quality of early stroke care was associated with lower long-term mortality following both ICH and ischaemic stroke, which emphasizes the importance of continued attention on the ability of stroke care providers to deliver high quality of early care.