The authors describe a rare case of congenital afibrinogenemia with concomitant K-dependent protein C deficit that was brought to our observation for ischemic lesions of the foot in association with fibrinogen concentrate infusions. These lesions can be attributed to the association of various factors: fibrinogen infusion without heparin coverage, microtrauma, and protein C (PC) deficit. In fact, thromboembolic complications during afibrinogenemia were previously reported usually in association with substitutive therapy, and it is also known that PC deficit predisposes to thrombotic complications. The the authors' knowledge, the case described by them is the first in which PC deficit is associated with afibrinogenemia. This association cannot be explained by a common genetic mechanism because the genes for fibrinogen and for protein C are located on different chromosomes (chromosomes 4 and 2 respectively).