Clinical guidelines recommend digoxin for patients with symptomatic systolic heart failure (HF) receiving optimal medical therapy, but this recommendation is based on limited, older trial data. We evaluated the effectiveness and safety of digoxin in a contemporary cohort of patients with incident systolic HF. We identified adults with incident systolic HF between 2006 and 2008 within Kaiser Permanente Northern California who had no prior digoxin use. We used multivariable extended Cox regression to examine the association between new digoxin use and risks of death and HF hospitalization, controlling for medical history, laboratory results, medications, HF disease severity, and the propensity for digoxin use. We also conducted analyses stratified by sex and concurrent ?-blocker use. Among 2891 newly diagnosed patients with systolic HF, 529 (18%) received digoxin. During a median 2.5 years of follow-up, incident digoxin use was associated with higher rates of death (14.2 versus 11.3 per 100 person-years) and HF hospitalization (28.2 versus 24.4 per 100 person-years). In multivariable analysis, incident digoxin use was associated with higher mortality (hazard ratio, 1.72; 95% confidence interval, 1.25-2.36) but no significant difference in the risk of HF hospitalization (hazard ratio, 1.05; 95% confidence interval, 0.82-1.34). Results were similar in analyses stratified by sex and ?-blocker use. Digoxin use in patients with incident systolic HF was independently associated with a higher risk of death but no difference in HF hospitalization.