The manuscript provides an overview of treatment and its changes in adult patients with haemophilia A without inhibitors in the Czech Republic between 2013 and 2021 using data from the registry of the Czech National Haemophilia Programme (CNHP). Over a 9-year period, we focused on the reduction in the annual bleeding rate (ABR), joint bleeding rate (AJBR) and factor VIII consumption when patients with severe haemophilia A switched from on-demand treatment to prophylaxis. The ABR and AJBR include both patient-reported home treatment and treated hospitalisation episodes. All adult patients with severe haemophilia A were categorised into three groups according to the therapeutic regimen. The first group was patients on prophylaxis during the follow-up period, the second group consisted of patients on on-demand treatment, and the third group was patients who received both treatment regimens during follow-up. With an increase in the proportion of patients with severe haemophilia A on prophylaxis from 37 to 74% between 2013 and 2021, the ABR for all patients with severe haemophilia A decreased approximately 6.9-fold, and the AJBR decreased 8.7-fold. Expectedly, the factor consumption increased by approximately 68.5%. In the group of patients with severe haemophilia A who had switched from an on-demand to a prophylactic regimen, the total number of bleeding events decreased 3.5-fold, and the number of joint bleeding episodes decreased 3.9-fold. Factor VIII consumption increased by 78.4%. Our study supports a previously reported positive effect of prophylaxis on bleeding control. We believe that the substantial improvement in ABR justifies the increased treatment costs.