Background. It has been demonstrated that graft survival rates of offspring-to-mother and husband-to-wife renal transplants are equivalent to those of other living donors. Although the vast majority of these transplants proceed without incident, hyperacute rejection can result from an anamnestic reaction subsequent to the in utero exposure of the mother to human leukocyte antigen (HLA) of the fetus with sensitization developing during the pregnancy. Patients and methods. Among 1350 renal transplants performed at our center, 12 corresponded to offspring-to-mother (G1) and 9 were husband-to-wife transplantations (G2). All recipients were multiparous (2 to 5 children). We compared these patients with other multiparous women (n = 150) who received grafts from living unrelated donors (153). Results. Two subjects in G1 (16.6%), two in G2 (22.2%), and none in G3 developed hyperacute rejection, which led to graft loss. One, 3-, and 5-year patient and graft survival rates were different between the remaining patients. Conclusions. Our limited experience suggested that, for some women, pregnancy is in fact a sensitizing event. A pretransplantation cross-match testing negative result was by no means an absolute guarantee that an adverse anamnestic immunological event would not occur.