Membrane surface characterization was studied by contact angles using both a goniometer and a tensiometer. It was checked that static and dynamic advancing contact angles of ultrafiltration membranes with water were in very good agreement. For glycerol and a-bromonaphthalene, dynamic advancing contact angles were sometimes different. Protein adsorption on polyethersulfone (PES) membrane was well evidenced whatever the solvent and closely related to the drying procedure. The efficiency of a nonionic surfactant (Tween 20) to desorb lysozyme from PES was discussed according to contact angles measured in the three liquids. Dynamic advancing contact angle of water on membrane after immersion-emersion loops was decreased and afforded likely a better characterization (polar contribution) of the membrane working in filtration conditions.