Between March 1983 and December 1989 a total of 57 pancreas transplants were performed in 54 patients, of whom 49 also received a kidney for end-stage diabetic nephropathy. Of the surviving 44 patients, 39 had regular pre-operative and post-operative ophthalmological examinations. Diabetic retinopathy was classified according to the original "Early treatment diabetic retinopathy study" (ETDRS) protocol. At the time of this analysis a total of 25 patients had a functioning pancreas transplant and 23 of them also a functioning renal allograft after a mean observation time of 43.2 months (Group 1). They were all free of exogenous insulin, HbA1c being 6.2% (5.1-6.9%; normal value 4.2-5.9%). Fourteen patients in Group 2 lost their pancreas transplant during the first four years. Six of them still have a functioning renal allograft, four patients regularly undergo hemodialysis. Mean HbA1c is 7.5% (5.7-9.2%). Before transplantation, grade of retinopathy according the ETDRS protocol was 6.7 (2-10) in group 1 patients and 7.9 (3-10) in group 2. In group 1 patients stabilisation of retinopathy was observed in 33 eyes (73.3%) and clear improvement achieved in 4 eyes (8.8%). Detoriation occurred in 8 eyes (17.7%) only. In group 2, 14 eyes (54%) remained stable, whereas progression of the disease continued in 12 eyes (46%). From these results it is concluded that the course of diabetic retinopathy is positively influenced by successful pancreas transplantation.