Of the saturated fatty acid-containing L-α-lysolecithins (LPC), palmitoyl-LPC shows the strongest antispasmodic effect against acetylcholine- or histamine-induced guinea pig ileum contraction; the order of potency of the others is (LysoPC(14:0/0:0)) myristoyl- > stearoyl-, lauroyl- > decanoyl-LPC. Incorporation of a cis-double bond into the C18 fatty acid chain of LPC resulted in a slight decrease of the antispasmodic effect.