Accurate age estimates for the commercially-important Caribbean spiny lobster, Panulirus argus, would greatly enhance analyses of life history and population dynamics. Previous estimates of their age based on size and growth may be inaccurate because of variable growth in the wild. An established technique for aging crustaceans – histologically-determined lipofuscin content in the nervous system – was used on lobsters reared in the laboratory for up to five years. We verified the presence of lipofuscin in eyestalk neural tissue and described its distribution in cell cluster A of the hemiellipsoid body. Neurolipofuscin content of both sexes increased linearly over the five-year age range, with seasonal oscillations. Growth of these animals, on the other hand, showed sex differences and began to asymptote after three years. Neurolipofuscin concentrations in the two eyestalks from the same animal were similar. These results suggest that the neurolipofuscin technique will be valuable for estimating age of wild-caught P.argus.