Over the last 10 years, the influence of the dog–owner relationship on dog behaviour has received growing attention, unlike the working dog handler's relationship. Using a questionnaire addressed to the 430 dog handlers of the Belgian army in 2001 (303 respondents), this study investigated the association between the time spent by handlers with their military dog (MD) and some behaviours of these dogs, reflecting welfare, obedience, and aggressiveness. Less than half of the handlers took their MD home and/or practised a sport with their MD. Most of the handlers practising sport with their MD also took their animal home. Statistically significant associations were detected. Obedience of MDs was clearly greater in MDs living at their handler's home and in MDs practising sport. On the contrary, we found no influence on obedience either for the first time handlers or for their length of service. Handlers taking their MD home and handlers practising sport with their MD declared fewer bites than the other handlers did. Bites concerned almost exclusively military staff. Only one family member was bitten by an MD and this MD had been left in a military kennel. Suspicion of previous rough handling was associated with fearful and aggressive behaviours. Handlers taking their MD home had dogs that were more sociable, this was not evidenced for MDs practising sport. Finally, being taken to a handler's home and practising sport were associated with a lower expression of behaviours indicative of impaired welfare. Discussion of our results in the field of dog-human relationship leads to conclude that the effects of housing at a handler's home and practising sport were strongly linked to the enhanced dog–handler relationship.