The age and growth of largemouth bass Micropterus salmoides in Lake Naivasha, Kenya, was determined using scales and otoliths collected in July 2002. Although validation could only reveal the likelihood of annual check formation on these structures, the subsequent growth outputs were valuable in revealing that M. salmoides were apparently growing at a rate in excess of those recorded from populations in more temperate regions. However, their life span appeared compromised, with no specimens recorded over the age of 4 . It was believed their limited life span was related to both their high exploitation in sport and commercial fisheries, and a trade-off between fast growth and longevity in individual fish.