Background: To determine the impact of heart failure (HF), with preserved or decreased left ventricular function (LVF), on outcome in patients with acute ischemic stroke (AIS)., Methods: We studied 503 unselected ischemic stroke patients. Poor outcome was defined as moderate-severe disability or death at 90 days. We analyzed the association between poor outcome and HF with preserved LVF or decreased LVF (systolic HF: ejection fraction lower than 50%). We tested this association adjusted by possible confounders in a logistic regression model., Results: 89 patients (17.7 %) had HF; 49 patients (9.7%) with systolic HF, and 40 (8%) patients with HF and preserved LVF. HF with preserved LVF patients were older [79.4 (7.9) vs. 74.3 (10.4), p = 0.013],more likely to be women [p < 0.001,OR = 8.61, 95% CI (3.3-22.6)], and with lower current smoking habits [p = 0.018, OR = 8.77 (1.1-72.6)] than patients with systolic HF. 151 patients (30 %) had poor outcome. We found an independent association with initial stroke severity, systolic HF (adjusted OR = 3.01), HF with preserved LVF (adjusted OR = 2.52), thrombolytic treatment, statin pre-treatment (as protectors) and poor outcome., Conclusion: Both forms of HF (with or without decreased systolic function) are associated with poor outcome in AIS.