Objective: β-blocking therapy is the standard therapy in non-operated Marfan patients, however its efficacy after entire aortic replacement is unknown. The aim of this study was to describe the influence of (nearly) entire aortic replacement and β-blocking therapy on blood pressure and wave reflections in Marfan patients. Methods: Four Marfan patients (mean age 31±3 years) and 8 age matched control subjects were studied. Blood pressure and wave reflections (reflection coefficient and augmentation index) were studied by means of magnetic resonance imaging, continuous non-invasive blood pressure measurements and applanation tonometry. Patients were studied with atenolol, labetalol and without β-blocking therapy. Results: In Marfan patients, aortic systolic pressure (129±13 vs 114±10 mmHg), pulse pressure (58±13 vs 40±5 mmHg), wave speed (11±3 vs 4±0.4 m s -1) and reflection coefficient (65±22 vs 41±5%) were significantly increased compared to controls. There was no difference in aortic pressure between various medications in Marfan patients (atenolol 129/76 mmHg, labetalol 121/75 mmHg and without β-blocking therapy 129/71 mmHg). Higher reflection coefficients were seen in patients with atenolol compared to discontinued medication (73±18 vs 65±22%), and also the augmentation index was higher with atenolol compared to labetalol and discontinued medication (24±22 vs 17±17 vs 22±22%, respectively). Conclusion: Our results describe increased pulse pressure, systolic pressure, wave speed and wave reflections in four Marfan patients after entire aortic replacement. The use of atenolol or labetalol did not decrease aortic pressure and with atenolol increased wave reflections were observed. Therefore, the beneficial effect of atenolol in these patients is doubtful.