Chronic wounds such as pressure ulcers and leg ulcers are common and cause considerable morbidity in both acute and community healthcare settings. Dressing therapy of these wounds remains empirical and to date there is little evidence to indicate which dressings are the most effective in their care. In the treatment of pressure ulcers some data indicate that hydrocolloid dressings seem to increase the proportion of healed ulcers compared with traditional saline-gauze dressings. There is no evidence that modern dressings are more effective than simple dressings (knitted viscose dressings or saline gauze) for the treatment of leg ulcers. Among modern dressings there is no evidence that any particular dressing type is more effective in healing pressure ulcers or leg ulcers. However, it should be emphasized that the level of certainty with which we can draw firm conclusions from the studies detailed in this review is greatly tempered by the methodological flaws and poor quality of many of the trials.