Data on in-hospital outcomes for hospitalizations undergoing thoracentesis (THR) for any cause has been conflicting. For hospitalizations with acute heart failure (HF), however, to date, no study has evaluated the outcomes of THR. Accordingly, our current study addresses this knowledge gap. We analyzed data from the Nationwide Inpatient Sample (2005-14). The study population included all adults (>18 years) with the principal discharge diagnosis of HF and the presence of procedure code for THR. Hospitalizations with pneumonia, acute kidney injury, and co-morbidities such as malignancy, lymphoma, liver disease, end-stage renal disease, metastatic disease, and tuberculosis were excluded. Propensity matching was performed to identify a similar cohort of admissions that did not undergo THR. Primary outcome of interest was in-hospital mortality and length of hospitalization. During the study period, 2,251,927 hospitalizations for HF were found from the database; of which, 70,823 (3.14%) had THR. After propensity matching, a matched cohort of 70,785 hospitalizations for HF was identified. In-hospital mortality was higher for those who underwent THR (2.5% vs 1.6%; p <0.001). In-hospital complications and procedures including cardiac arrest, sepsis, pneumothorax and hemothorax were more frequent in the THR group. Those who underwent THR had a longer mean length of stay (6.9 vs 4.5 days; p <0.01) and higher cost of hospitalization ($13,448 vs $ 8940; p <0.01). The trend analysis demonstrated a steady increase in the performance of THR in hospitalized HF between 2005 and 2014. In conclusion, THR performed during HF hospitalizations were associated with higher rates of in-hospital mortality, complications and increased healthcare utilization in the form of longer length of stay and higher costs.