Fifteen species of poecilostome copepods associated with marine invertebrates, including ten new species, are recorded from intertidal zone in Thailand. New species are Hemicyclops cornutus n. sp. and Hemicyclops parapiculus n. sp. in the family Clausidiidae, Presynaptiphilus trifurcatus n. sp. in the Synaptiphilidae, Anchimolgus kantariensis n. sp. and Anchimolgus palmatus n. sp. in the Anchimolgidae, Kelleria vasfera n. sp. in the Kelleridae, Pseudanthessius stenosus n. sp. and Pseudanthessius phuketensis n. sp. in the Pseudanthessiidae, Doricidola pattayensis n. sp., and Lambanetes mollis n. sp. in the Rhynchomolgidae. Five species are new records of Thailand: Critomolgus gemmatus (Humes, 1964), Doridicola cuspis (Humes, 1964), Doridicola inaequalis (Humes and Ho, 1966), Indomolgus brevisetosus (Humes and Ho, 1966), and Lambanetes stichodactylae Humes, 1982. The female of Lambanetes stichodectylae is described for the first time in the world.