Objective: To investigate a family with factor VII (FVII) deficiency from Argentina. Patients and Methods: The proposita is a 14-year-old girl who presented with a mild to moderate bleeding tendency. Menorrhagia is controlled with periodical administration of small doses of recombinant FVII concentrate. The mother of the proposita has a similar bleeding tendency. Results: FVII activity in both patients was 20% of normal; FVII antigen was 35% of normal. Molecular biology investigation revealed that the proposita was compound heterozygote between Thr384Met and Arg413Gln. The mother had the same mutations. This was due to the fact that the father of the proposita and her maternal grandfather both carried, in spite of no relation, the same mutation, namely Arg413Gln. Conclusions: The identical defect which presented in the proposita and her mother could be explained by the genetic analysis of the father and maternal grandfather of the proposita who happened to have the same mutation (Arg413Gln).