Background: Streptococcus bovis is a classical etiology of endocarditis and is associated with colonic lesions. No series of cases from Brazil has been described. Objectives: To describe aspects of S. bovis endocarditis. Methods: This is a case series of patients admitted to a cardiac surgery referral center, during the years 2005–2014. Clinical, laboratory, echochardiographic, colonoscopic, treatment, surgical and outcome variables were studied. Results: Nine patients with S. bovis endocarditis were included; all cases fulfilled the modified Duke criteria. Incidence was 8/220 (4%) in years 2006–2014. There were seven male and two female patients; mean age was 56.7 years, standard deviation 13.4. All patients had native aortic valve involvement. Presentation was subacute in 7/9 (71%). Fever was present in 7/9 (77.7%), embolic lesions to solid organs occurred in three, and perivalvular abscess in two patients. All echocardiograms showed moderate to severe valvular regurgitation and vegetations. Microcytic anemia was seen in 7/7 patients. Colonoscopy showed abnormal findings in 7/9 (77.7%). Surgery was indicated for 6/9 patients due to acute aortic regurgitation and left ventricular failure. All patients were discharged home. Conclusions: S. bovis most frequently affected the aortic valve of male patients. Colon disease was frequent. Surgery was indicated frequently due to hemodynamic compromise.2023-01-28