Evidence that distinct types of shapes and movement can be induced by different neutrophil-activating agents like the chemotactic peptides and PMA is reviewed. Front-tail polarity seems to be preferentially associated with locomotion, whereas non-polar cells with surface projections show preferentially pinocytosis. The following partially hypothetical concept on neutrophil shape changes has been derived from these experiments: Neutrophils are capable to perform distinct types of movements depending on the stimulus or stimuli. Distinct movements are preferentially associated with distinct functions such as locomotion, pinocytosis or others. The underlying cytoskeletal changes may differ accordingly.