A new bone tissue process using supercritical carbon dioxide extraction was evaluated for viral inactivation and the allografts produced by this process were tested in an in vivo implantation experiment. Four viruses, human immunodeficiency virus type I (HIV-1), Sindbis virus, Polio Sabin type I virus and Pseudorabies virus (PRV) were assayed. Four processing stages, supercritical CO,, hydrogen peroxide, sodium hydroxide and ethanol treatments were also tested. The efficiency of the process was assessed in terms of reduction factors which are the log,, of the ratio of the virus load before and after the stage to be evaluated. The cumulated reduction factors were the following: > 18.2 for Sindbis virus, > 24.4 for Poliovirus, > 17.6 for PRV and > 14.2 for HIV-1. Such allografts processed in this way were implanted into sheep leading to a much faster osseointegration in comparison with non-treated allografts. The combination of better graft incorporation and viral safety suggest that this process could become a new way for processing bank bones, alternatively or additionally, to the procedures presently used.