Samples of Loligo gahi from the Falkland Islands Interim Conservation and Management Zone collected in March 1987 were analysed to determine the relationships between mass of reproductive and somatic organs during maturation. There was a progressive increase in mass of the reproductive organs with growth in males, while in females these organs did not show a conspicuous increase in mass until a body mass of c. 40 g was reached. No change was found in the mass of the digestive gland in relation to body mass or in the water content of male and female somatic tissues during maturation. Growth of reproductive organs in L. gahi seems to be supported by diet and not at the expense of somatic tissue.