Phosphoinositide 3-kinases (PI3Ks) are a family of lipid kinases that phosphorylate the 3' OH position of the inositol ring of phosphoinositides on the inner leaf of the plasma membrane. Receptor-mediated activation of the PI3K pathway plays a crucial role in numerous signaling pathways and regulates a number of critical cellular processes, including growth, differentiation, survival and directed migration. In this focus article, we review the temporal and spatial regulation of PI3K in chemotaxing cells with particular emphasis on the amoeba Dictyostelium as well as neutrophils. We also briefly discuss one model used to elucidate the PI3K pathway.