A novel antiseptic biguanide has been shown to be more bactericidal and tissue compatible in vitro than other antiseptics. In our controlled, prospective and randomized double-blind study on patients with bacteria-contaminated wound types 2-4, one group (n = 45) was treated with humid cotton swab dressings of 0.2% Lavasept solution compared with Ringer solution (n = 35). No deterioration of wound healing was observed in either group. Lavasept treatment resulted in faster and significant reduction of gram-positive germs. The tissue compatibility of Lavasept was evaluated as significantly better than Ringer solution.