Aims: Infections are associated with worse short-term outcomes in patients with heart failure (HF). However, acute infections may have lasting pathophysiologic effects that adversely influence HF outcomes after discharge. Our objective was to describe the impact of acute bacterial infections on longitudinal outcomes of patients hospitalized with a primary diagnosis of HF. Methods and Results: This paper is based on a retrospective cohort study of patients hospitalized with a primary diagnosis of HF with or without a secondary diagnosis of acute bacterial infection in Optum Clinformatics DataMart from 2010–2015. Primary outcomes were 30 and 180-day hospital readmissions and mortality, intensive care unit admission, length of hospital stay, and total hospital charge, compared between those with or without an acute infection. Cohorts were compared after inverse probability of treatment weighting. Multivariable logistic regression was used to examine relationship to outcomes. Of 121,783 patients hospitalized with a primary diagnosis of HF, 27,947 (23%) had a diagnosis of acute infection. After weighting, 30-day hospital readmissions [17.1% vs. 15.7%, OR 1.11 (1.07–1.15), p < 0.001] and 180-day hospital readmissions [39.6% vs. 38.7%, OR 1.04 (1.01–1.07), p = 0.006] were modestly greater in those with an acute infection versus those without. Thirty-day [5.5% vs. 4.3%, OR 1.29 (1.21–1.38), p < 0.001] and 180-day mortality [10.7% vs. 9.4%, OR 1.16 (1.11–1.22), p < 0.001], length of stay (7.1 ± 7.0 days vs. 5.7 ± 5.8 days, p < 0.001), and total hospital charges (USD 62,200 ± 770 vs. USD 51,100 ± 436, p < 0.001) were higher in patients with an infection. Conclusions: The development of an acute bacterial infection in patients hospitalized for HF was associated with an increase in morbidity and mortality after discharge.