Abstract <p>Due to the features of their life cycle, deep-sea fishes are more vulnerable to overfishing than many other species. The intensification of fishery for giant grenadier <i>Coryphaenoides pectoralis</i> in the Russian Far Eastern seas requires special attention to the rational management of stocks of this species, including through a correct understanding of the size and age structure of its populations. The current and historical estimates of the giant grenadier lifespan vary from 8 to 58 years or more. An analysis was carried out based on the prepared preparations for age determination, which has shown that the age determined by the scales is significantly underestimated compared to that obtained from otolith thin sections. The maximum age of females in the sample, determined by scales, reached 13 years and that determined by otoliths was 23 years; the maximum age of males was 10 and 21 years, respectively. The methodology for determining the age by otolith thin sections does not exclude the underestimation of the first and marginal annual rings of otoliths. The question of interpreting the annual marks on otoliths has not yet been fully resolved. Further research is required to expand the understanding of the growth of the grenadier. For fishery purposes, it is proposed to estimate the age by otoliths.</p>