The curve used until recently by the International Commission for the Conservation ofAtlantic Tunas (ICCAT) to represent the growth of western Atlantic bluefin tuna,Thunnus thynnus, was estimated using tagging information and modalsizes that corresponded primarily to very young fish (ages 1–3, primarily). The estimatedmaximum average size from this curve is very large (382 cm), which could be a result ofthe scarcity of large bluefin in the data used. Recently, scientists have developedtechniques for reading ages from bluefin ear bones (otoliths); the accuracy of the agereadings has been validated with bomb radiocarbon dating. These age readings are primarilyfor large bluefin (ages 5 and older), and indicate slower growth and older ages than waspreviously assumed. However, an analysis of these data resulted in growth curves thatpredicted very small mean sizes for the youngest age group, which could be a result of thelack of small fish in the data used. In this study, we combine the otolith-based agereadings with the size frequency distributions of small (ages 1–3) bluefin caught by purseseiners in the 1970s where the age groups are distinctly statistically as well as visibleto the eye. We analyzed the two datasets jointly using a maximum likelihood approach andassumed that variability in length-at-age increases with age. The resulting growth curvepredicts sizes at young and old ages that are very consistent with observed data such asthe maximum sizes observed in the catch and the modal sizes for very young bluefin. Theresulting curve is also very similar to the curve used by ICCAT for eastern Atlantic andMediterranean bluefin.