Effusion-based lymphomas (EBL) are usually high-grade B cell non-Hodgkin's lymphomas which involve effusion fluid in a body cavity, typically presenting as a pleural effusion, without evidence of disease elsewhere. They are most frequently seen in HIV-infected individuals and are biologically driven by human herpesvirus-8 virus (HHV-8). HHV-8 (+) EBL is recognized as primary effusion lymphoma (PEL) under the World Health Organization classification. HHV-8 (-) EBL has been reported in association with Hepatitis C virus (HCV) infection, Epstein-Barr virus (EBV) infection, fluid overload, liver cirrhosis, renal dysfunction, cardiac arrhythmias, myocardial infarction, and heart failure. These cases can be labeled as primary EBL (PEBL). We describe a non-germinal center B cell diffuse large B cell lymphoma (NGCB-DLBCL) presenting as PEBL in an immunocompetent 81-year-old male who had an extensive cardiac history and tested negative for HIV, HHV-8, and EBV. He was treated with thoracentesis and standard anthracycline-based chemoimmunotherapy and has remained in complete remission for over 5 ½ years since his original diagnosis. Our case indicates that NGCB-DLBCL can present as PEBL and is potentially curable with the standard chemoimmunotherapeutic approach.