Species and distribution of Penaeoid shrimps in Thailand were studied in specimens of shrimp collected from fish markets and fishing ports of 23 provinces along the Gulf of Thailand and the Andaman Sea coast. Identification of species was based on the morphological characters of rostrum, carapace, branchiae, antennule, antenna, third maxilliped, pereiopods, pleopods, abdomen, telson, petasma, thelycum, and the colored pattern of the whole body based on keys and diagnoses available from the current literature. A total of 50 species from 13 genera and 3 families of Penaeoidea were identified in coastal provinces of the Gulf of Thailand and the Andaman Sea. Additional research is needed to more clearly define the distribution of shrimp species in the Gulf of Thailand and the Andaman Sea coasts.