In insects, neuropeptides are important messenger molecules which influence on developmen- tal, reproductive and behavioural processes. In the past few years large number of new neuropeptides has been identified from insects. They can act as transmitters, modulators and classical hormones and often exhibit pleiotropic functions including myotropic activity. We summarize the current knowledge on primary structures and physiological functions of three different groups of myotropic neuropeptides in insects: tachykinin-related peptides, sulfakinins and FMRF-amide-related peptides.