Diagnosing lead‑related infective endocarditis (LRIE) often poses a substantial challenge. Current diagnostic criteria include definite and possible LRIE. The aim of this study was to compare the outcomes of patients with definite and possible LRIE undergoing transvenous lead extraction (TLE) procedures. A retrospective analysis of data from 3782 patients undergoing TLE between 2006 and 2023 was performed. The study included 838 patients with definite and possible LRIE, whose clinical data on short- and long‑term survival were evaluated. The comparison of clinical data showed more frequent occurrences of vegetations (81.58% vs 37.21%; P <0.001), positive blood cultures (66.12% vs 51.64%; P <0.001), and septic pulmonary embolism (40.14% vs 13.78%; P <0.001) in the patients with definite LRIE. Long‑term mortality of patients with definite and possible LRIE (median [interquartile range] follow-up, 4.61 [1.04-9.4] and 5.06 [2.07-8.75] years, respectively) was 61.14% and 49.29% (P <0.001). Predictors of mortality in patients with definite LRIE included: advanced age, low left ventricular ejection fraction (LVEF), comorbidities, septic pulmonary embolism, positive blood culture, and presence of an abandoned lead. In possible LRIE, only the influence of advanced age, low LVEF, and comorbidities was demonstrated. There was no documented evidence of a direct impact of a delayed diagnosis on the long‑term survival of patients after TLE. The study showed better survival in patients with possible LRIE than with definite LRIE, which confirms the need to extend the diagnostic criteria. Introducing appropriate treatment at an early stage of infection improves the prognosis.