The repair process of rabbit corneal alkali wounds was examined for 3 weeks in organ culture. The initial wound was inflicted by applying a round filter paper, 5.5 mm in diameter, soaked in 1 N NaOH, for 60 s on the central cornea--the same procedure as used in previous in vivo studies. Epithelial and endothelial healing were determined morphometrically by utilizing a standardized photographic procedure following alizarin red/trypan blue staining. A one-phase healing was discerned both in the epithelium and in the endothelium. The epithelial resurfacing of the wound was completed by 5 days and then remained intact. However, the endothelial defect did not heal completely during the observation period of 21 days. The defect area was, however, consistently reduced in size during the first four days. The present results were compared with previous in vivo findings in rabbit eyes. The advantages of using an in vitro model for initial therapeutic trials are described.