An in vitro approach was used to obtain information about the compatibility of hydroactive dressing materials with the serum proteins which are thought to be relevant to wound healing. Artificial wound fluid was incubated with different hydroactive dressings (Cutinova hydro, Varihesive E, Comfeel Ulcer Dressing and Allevyn), and concentrations of total protein, albumin, immunoglobulin and growth factors were measured after one day of incubation. Cutinova hydro and Allevyn absorbed considerable amounts of fluid. Fluid uptake was lower for the hydrocolloid dressings. An unexpected finding was that Cutinova hydro showed an approximately two-fold increase over control values in the concentration of all proteins tested, indicating a selective absorption of water by this dressing. For the other dressings tested, zero or very low absorption of proteins was found, indicating a basically satisfactory protein compatibility.