Isolated acquired factor VII deficiency is uncommon. We report 11 cases of acquired factor VII deficiency associated with severe systemic sepsis. All patients initially displayed a heterozygous-like factor VII deficiency confirmed by both clotting and amidolytic assays, associated with low factor VII antigen levels, and increased haemostasis markers (D-dimers, prothrombin fragments 1.2, thrombin-antithrombin complexes). After sepsis recovery, normal factor VII levels were evidenced. Isolated factor VII consumption or proteolytic degradation by leucocyte proteases can be evoked, but the mechanism of acquired factor VII deficiency during sepsis remains to be elucidated. The knowledge of this syndrome should avoid false diagnosis of congenital factor VII deficiency.