BACKGROUND: The impact of acute heart failure following acute ischemic stroke on short-term cardiovascular outcomes remains unclear. This study investigated the association between acute heart failure and cardiovascular outcomes within 90 days after acute ischemic stroke. METHOD AND RESULTS: We retrospectively analyzed 1658 patients with acute ischemic stroke. In-hospital heart failure was defined as heart failure diagnosed on admission or within seven days of hospitalization. The primary outcome was a composite of major adverse cardiovascular events within 90 days of acute ischemic stroke. Secondary outcomes included a composite of fatal or nonfatal heart failure and all-cause mortality. Logistic regression analyses were used to identify predictors of these outcomes. Eighty-two patients with acute ischemic stroke (4.9 %) developed acute heart failure. Major adverse cardiovascular events occurred in 120 patients (7 %) within 90 days. In-hospital heart failure was an independent predictor of major adverse cardiovascular events (odds ratio [OR] 2.25, 95 % confidence interval [CI] 1.11-4.53, p = 0.023) and fatal or nonfatal heart failure (OR 4.72, 95 % CI 1.96-11.35, p = 0.002) within 90 days. However, it was not a significant predictor of all-cause mortality (OR 1.90, 95 % CI 0.94-3.84, p = 0.075). CONCLUSIONS: In-hospital heart failure was a significant predictor of major adverse cardiovascular events and fatal or nonfatal heart failure within 90 days after acute ischemic stroke.