This study was designed to determine the potential value of dog-appeasing pheromone (DAP) in reducing behaviours associated with fear of unfamiliar people and new surroundings in puppies newly adopted from a pet shop. The study was triple-blinded, randomised and placebo-controlled. It used 66 puppies (32 fitted with a DAP collar and 34 control) and the adoptive owners were contacted by phone three days and 15 days after they had adopted the puppy to question them about its reactions to specific situations eliciting fear. Fifteen days after the treatments significantly fewer of the puppies with the DAP collars showed signs of fear when facing unfamiliar people at home and/or during outings. This difference was irrespective of breed size.