The incidence of intraglomerular thrombi in renal allografts and factors regulating their resolution were studied. A case report is presented in which resolution of intraglomerular thrombi is documented. In addition, 17 transplanted patients with renal biopsies were serially studied. Intraglomerular thrombi were found in 4 of 8 specimens taken 1 h after reanastamosis, all from donors with a terminal course involving prolonged hypotension. Glomerular fibrinolytic activity was markedly diminished in 4 of 11 patients’ subsequent biopsy specimens; all taken during acute rejection. Resolution of thrombi was documented when signs of rejection were absent.