SUMMARY.A National Register of transfusion‐transmitted infections was opened by the French Society of Blood Transfusion on 1 October, 1986. Out of 54 initially reported cases of HIV‐infection, allegedly transmitted by blood components, further investigation could be completed in 33 cases. The transfusional origin of contamination was considered as established or probable in 28/33 cases, either because a potentially infectious unit was identified among those transfused to the recipient (23/28), or because the recipient was known to be seronegative before transfusion (5/28), or both (10/28). In 5/33 cases transfusion was considered as presumably responsible for contamination because no other risk factor was found in the recipient.Among the 33 documented cases of HIV‐transmission by screened blood, 29 (88%) occurred between 1985 and 1987, and four (12%) during 1988.Out of 19 implicated donors later found seropositive, 16 belonged to a high‐risk group for HIV‐infection. The majority of HIV‐infections occurred as a consequence of blood donation in the window period between contamination and the appearance of detectable antibodies in the donor's serum (11/19). In three instances, however, human and operational errors led to the release of seropositive units.We conclude that the main value of this Register is to provide a potential trend‐indicator of transfusion‐related infectious risks, to allow objective documentation of reported cases and to contribute to the improvement of blood trans