A firm understanding of the early selection efficiency of ring widthwood quality traits is a prerequisite for breeding of higher growth rateswood quality of slash pine (Pinus elliottii Engelm.). To accomplish effective early selection for the studied traits, wood core samples were collected from 360 trees of 20 open-pollinated families from three slash pine rotation-aged (harvest age) genetic trials. Wood cores were measured by SilviScan,the annual patterning, heritability, age-age genetic correlationefficiency of early selection for ring width, modulus of elasticity (MOE), microfibril angle (MFA)wood density for early to reference age (age 27) were investigated. The greatest annual ring width was observed at age 4,this trait decreased gradually toward the bark. Different radial trends were found for MOEMFA. Wood density was lowest near the piththen increased steadily with age. Overall, heritability was moderate to high for all area-weighted wood quality traits. Very high age-age genetic correlation values were observed for all traits researched. Estimates of efficiency for early selection indicated that the optimal age of early selection for ring width was 9-12 years, while that for area-weighted MOE, MFAwood density was 7-8 years.