Abstract Background Transient bacteremia is a well-known complication of transurethral resection of the prostate (TUR-P). Still, the associated risk of bacteremia and subsequent infective endocarditis (endocarditis) after TUR-P has been sparsely examined. Purpose To examine the risk of bacteremia and infective endocarditis following TUR-P. Methods We identified all patients who underwent TUR-P between 2010-2020 with ICD-10 codes from Danish nationwide registries. Patients were compared to an age-matched cohort of males from the general population (1:1 match-ratio). We defined a 6-month exposure window following TUR-P and examined the risk of bacteremia and endocarditis within the first 6 months and compared with the following 6-12 months after TUR-P. Microbiology findings were based on complete data on blood culture results. Incidences of bacteremia and endocarditis were calculated, and groups were compared with cumulative incidences. To account for predisposing endocarditis risk factors, multivariable time-dependent Cox regression analyses were performed on the associated risk of bacteremia and endocarditis. Results In total, 25.781 patients underwent TUR-P. Median age was 70.7 years (IQR: 64.9-76.3). Incidence of bacteremia was higher in the TUR-P group than the control group (727.47 [681.49-776.56] per 10,000 person years vs 84.75 [95% CI: 70.19-102.35)] per 10,000 person years). Incidence of endocarditis was also higher in the TUR-P group than the control group (34.64 [95% CI: 25.78-46.55] per 10,000 person years vs 3.14 [95% CI: 1.18-8.35] per 10,000 person years). In 72.7% of endocarditis-cases, Enterococcus Faecalis was the disease-causing pathogen in the TUR-P group. As compared with an age-matched control group, we found an increased associated risk of bacteremia in patients undergoing TUR-P within the first 6 months from the procedure (adj. HR: 7.72 [95% CI: 6.25-9.53]) and the increased risk persisted within the following 6-12 months (adj. HR 2.31 [95% CI: 1.83-2.91]). TUR-P was also associated with endocarditis within 6 months from the procedure (8.16 [95% CI 3.06-21.79]), but not significantly the following 6-12 months after (2.15 [95% CI: 0.91-5.07]) as compared with the age-matched control group. Conclusion Transurethral resection of the prostate (TUR-P) is associated with an almost 8 times increased risk of bacteremia and an 8 times increased risk of infective endocarditis. Our findings emphasize the necessity for development of better preventive strategies against infective endocarditis after TUR-P.Risk of endocarditis post-TUR-P