INTRODUCTION: The aim of this study was to compare the treatment effect of aortic stenosis through surgical and percutaneous valve replacement by analyzing the reduction of maximal transvalvular pressure gradient. PATIENTS AND METHODS: This retrospective study included 415 patients diagnosed with aortic stenosis who underwent surgical or percutaneous valve replacement from the beginning of 2017 to the end of 2022 at the Clinical Hospital Center Zagreb. The data were extracted from the hospital digital database and the "EchoPAC" program. The patients were divided into two groups: those treated with surgical aortic valve replacement (SAVR) and those treated with transcatheter aortic valve replacement (TAVI). Their age, gender, comorbidities and echocardiographic parameters (max. PG and EFLV) were analyzed. RESULTS: Out of the total number of patients, 209 underwent surgical valve replacement, while 206 underwent percutaneous valve replacement. Patients treated with TAVI were significantly older (mean age 80,3 years) compared to the surgical group (mean age 68,7 years; p<0.001). A more effective reduction of maximal transvalvular pressure gradient was observed in the TAVI group compared to SAVR (73.2% and 65.4% respectively; p<0.001). Additionally, lower values of max. PG were observed after the procedure in the TAVI group (p<0.001), as well as a more effective reduction with increasing age in that group. The ejection fraction value increased in a higher percentage of patients after TAVI procedure (61.7%) compared to surgical intervention (48.8%; p=0.029). Statistical analysis did not show a correlation between the change in EFLV values and the degree of reduction of max. PG after the procedure (p=0,913). CONCLUSION: Considering the reduction of max. PG after the procedure, transcatheter valve replacement has shown to be a more effective method in treating patients with aortic stenosis compared to surgical replacement.