Mast cells accumulate at local tissues in different pathophysiological conditions, including both acute and chronic inflammation. It is well established that mast cell recruitment is mediated by different humoral factors, that act as mast cell chemoattractants. The aim of our study was to examine the ability of three cytokines, i.e. TNF-a, IL-6 and IL-4, to mediate rat peritoneal mast cell migration. We have found that IL-4 and IL-6 did not act as rat mast cell chemoattractants, whereas TNF-a significantly influenced rat mast cell migratory response. This cytokine at concentrations from 10-6 ng/ml to 5 x 10-4 ng/ml caused a statistically significant increase in mast cell migration with a maximal response at concentration 5 x 10-5 ng/ml. Higher concentrations of TNF-a, ranging from 0.01 ng/ml to 100 ng/ml, induced significant inhibition of mast cell migration. Checkerboard analysis indicated that migration of mast cells towards TNF-a was mainly chemotaxis and in part ensured from chemokinesis. Thus we have stated that TNF-a is a potent factor which influences rat mature mast cell migration in tissues.