It has been shown that Belgian military working dogs exhibit fearful and aggressive behaviour towards human and unknown environment. This study aims to assess the effects of a Human Familiarisation and Training Programme (HFTP: based on positive and frequent dog-handler interactions and training) on fearfulness and aggressiveness of military working dogs. Authors predicted that an Experimental Group of dogs submitted to this HFTP (=EG dogs) would be less fearful and aggressive during a standardised aggression test than a Control Group of dogs (CG dogs). Higher posture, less yawning and less aggressive behaviours were observed among EG dogs. Authors interpreted those differences in fearfulness and aggressive behaviour as a positive effect of this HFTP on dog's welfare and concluded that this HFTP induced a better working dog-handler relationship.