Nowadays, the elective treatment for children with haemophilia is prophylaxis. There is a common consensus that this modality of therapeutic approach is not associated with a higher risk of inhibitor development. We analysed the inhibitor incidence in 50 haemophiliac children and its relationship with mutations, type of clotting factor used and treatment modality. There was a significant correlation between receiving on-demand treatment and an increased incidence of inhibitors, independently of mutations or factor used. We advise putting haemophiliac children under prophylactic treatment as soon as possible, especially if they have mutations associated with high risk of inhibitor development, as prophylaxis is negatively associated with the development of inhibitors.