The present investigation describes the biology of penaeid shrimps and their fishery studies on morphometric length-weight relationships estimated during the two monsoon seasons from Malindi–Ungwana Bay in Kenya. A total of 1238 penaeid shrimps belonging to Fenneropenaeus indicus, Penaeus monodon, Marsupenaeus japonicus, Metapenaeus monoceros, Penaeus canaliculatus and Penaeus semisulcatus were collected from the two seasons with South East Monsoon (SEM) recording more diverse species than the North East Monsoon (NEM). The length-weight relationship analyses of most penaeid species exhibited positive allometric growth significantly different from 3.0 (p