Information on the age and growth of fish is usually related to one or several of the following items: construction of age/length keys for direct use in some assessment models (e.g. Virtual Population Analysis); estimation of growth parameters, used as inputs in some other models (e.g., yield-per-recruit); comparative studies of growth performance in different stocks and species (i.e., in studies of environmental factors affecting growth); and studies of the anatomical and physiological mechanisms underlying the growth performance in fish. The relative importance of these aspects is discussed in the context of fisheries management in the Northeast Atlantic, Kuwait and Southeast Asia, which are considered as representative of three major types of situations encountered worldwide in fishery management.