It is generally accepted that keratinocyte migration plays a critical role in the process of wound healing. A study was therefore made of the migratory response of freshly separated and cultured human keratinocytes to factors with chemotactic properties for a variety of cells. Interleukin-1 alpha (IL-1 alpha), interferon-gamma (IFN-gamma), interleukin-8 (IL-8), and tumour necrosis factor alpha (TNF-alpha) were tested for their chemotactic effectiveness in a modified Boyden chamber assay. IFN-gamma, IL-1 alpha and IL-8 were demonstrated to serve as chemoattractants for freshly separated keratinocytes. For cultured cells, however, only IFN-gamma was found to display chemotactic properties. The findings demonstrate that there is significant difference between the chemotactic behaviour of freshly separated and cultured cells.