Dictyostelium discoideum displays chemoattractant-directed cell migration typical of many higher cell types. Signaling through chemoattractant receptors involves a standard G-protein-linked pathway. Genetic analysis has distinguished essential and dispensable components and demonstrated that some signaling events are independent of G proteins. Genetic analysis has also led to the identification of additional genes involved in chemosensory transduction. Further studies on the newly discovered components and pathways should help in elucidating the molecular mechanisms of eukaryotic chemotaxis.