Renal vein thrombosis (RVT) is most often an implication of nephrotic syndrome. Pyelonephritis has been associated at a much lower rate, with the incidence of Klebsiella pneumoniae causation being extremely rare. In our case, a 35-year-old female patient presented with right-sided K. pneumoniae-positive acute pyelonephritis complicated by perinephric abscess and renal vein thrombosis. She was successfully treated with anticoagulation and extended antibiotic therapy. The possibility of RVT in patients with K. pneumoniae-induced pyelonephritis warrants consideration.