We report a case of severe acute kidney failure due to crescentic glomerulonephritis who presented initially with culture-negative endocarditis with vegetations on the aortic valve. Anti-nuclear and anti-phospholipid antibodies were positive with initially negative anti-neutrophil cytoplasmic antibodies (ANCAs). Kidney biopsy revealed severe acute crescentic glomerulonephritis with mesangial immune complex deposition. PR3-ANCA subsequently become positive, and the patient developed worsening kidney failure requiring hemodialysis. This case illustrates that Bartonella can present as culture-negative endocarditis with severe crescentic glomerulonephritis with positive PR-3 ANCAs and can mimic ANCA-associated crescentic glomerulonephritis.