A 48 well chemotaxis microchamber, originally designed for use with polycarbonate filters, was used with nitrocellulose filters to quantitate chemotaxis and chemokinesis of granulocytes. Various features of the microchamber were compared to Boyden chambers. The accuracy and reproducibility of the method were found to be comparable to Boyden chambers in the variability between individual readings and superior in the variability between replicate values. Concentrations of optimal doses of chemoattractant for chemotaxis and chemokinesis were similar using both types of chamber. The data indicates that this method may be useful in studying components of the chemotactic response which require the use of cellulose filters. Advantages of this method over standard Boyden chambers include the use of a single filter rather than individual, non-identical filters and a reduction in the number of cells required, particularly for pediatric testing or in neutropenic patients.