A total of 230 otoliths was used for age and growth analysis of Spanish mackerel (Scomberomorus maculatus) in the northern Gulf of Mexico. Male fish in the sample ranged from ages 0 to 6, whercas females were 0 to 4 years old. Females exhibited faster growth than did males. Von Bertalanffy growth equations were: males L = 552( I - e -0'''''+ 16h,), and females L = 604(1 - e 04'" ")751). Growth equations from this study showed that both sexes grew at significantly slower rates than did Spanish mackerel in south Florida waters. Age-frequency distributions showed a differential pattern of mortality between the sexes from ages I through 4. Females showed a 50% decline in numbers bctween ages I and 2, whereas males exhibited a decline of 80% between ages 2 and 3. The differential growth and age specific mortality patterns imply that males and females entcr the fishery at different ages and that the fishery is contributing noticeably to total mortality. Fishery management alternatives are discussed.