{Reference Type}: Journal Article {Title}: Expect the unexpected: endocarditis caused by Legionella feeleii. {Author}: Moran A;Otero Espinal DE;Parilla M;Beavis KG;Mullane KM;Tesic V; {Journal}: Lab Med {Volume}: 0 {Issue}: 0 {Year}: 2024 May 23 {Factor}: 1.865 {DOI}: 10.1093/labmed/lmae029 {Abstract}: We report a fatal case of Legionella feeleii endocarditis in a post-lung transplant patient. The diagnosis was delayed, as routine microbiological testing of nonrespiratory specimens does not account for extrapulmonary Legionella, and urine antigen testing only reliably detects Legionella pneumophila serogroup 1. This case also illustrates the utility of molecular sequencing for blood culture-negative endocarditis.