Objective: To assess the effect of emicizumab on physical activity in children with severe haemophilia A. Method: The prospective cohortstudy was conducted from October 2021 to April 2022 at the Paediatric Department of Kafrelsheikh University Hospital, Egypt, in collaboration with the Haematology out-patient clinic of the Paediatric Department, Zagazig University, Egypt, and the Paediatric Department of Cairo University Hospital, Egypt, and comprised children aged 4-18 years with severe haemophilia A who received emicizumab prophylaxis. Paediatric Haemophilia Activities List was used to assess physical activity at baseline and aftersix months of regular emicizumab prophylaxis. Data was analysed using SPSS 26. Results: There were 29 children, all (100%) boys, with mean age 8.7±3.51 years(range 4-15 years. Of them, 17(58.62%) patients were negative for inhibitors. Median Paediatric Haemophilia Activities Listsum score was 59.54 (interquartile range: 50.15-62.05) at baseline which moved up to 84 (interquartile range: 79.05-86.35) post-intervention (p<0.001). Conclusion: Emicizumab prophylaxis improved the level of physical activity in children with severe haemophilia A. Keywords: Emicizumab, Haemophilia, Haematology, PedHAL