Expression of early genes is a characteristic immediate cellular response to mitogenic or inflammatory stimulation. Various second messenger systems have been found to transduce the signal from the plasma membrane to the nucleus. Recent observations indicate that in addition to well characterized second messenger systems, polyunsaturated fatty acids, especially the n-6 fatty acid arachidonic acid and its endogenously produced metabolites affect the expression of early genes in different cell types. At least in fibroblasts, the stimulatory effect of arachidonic acid can be antagonized by n-3 polyunsaturated fatty acids. Further identification of the mechanisms through which polyunsaturated fatty acids modulate early gene expression and regulate subsequent cellular responses, like cell growth, may help to define novel concepts in the management of cardiovascular diseases.