Inclusion of wood quality traits in Eucalyptus selection and breeding strategies is becoming an important goal whatever the end uses are. Chemical, physical or anatomical characteristics affect both paper, sawn wood and charcoal yield and quality but the complex trait-trait relationships and the effect of growth are still poorly known. Choice of relevant characters for breeding, selection efficiency and genetic gain heavily rely to heritability values and magnitude of phenotypic variation within the breeding population as well as to genetic correlation between traits. Recent development of cost effective tools such as near infrared spectroscopy or automatic fibre measurement allow multi-trait assessment of large populations needed to provide genetic parameter estimations. Multi-trait analysis of a full sib Eucalyptus urophylla x E. grandis 4 x 5 factorial mating design was performed for basic density, heartwood/sapwood ratio, fibre dimensions using traditional tools and using near infrared spectroscopy for lignin and extractives contents. This study provides estimation of heritability and trait-trait genetic correlations. The choice of characters and the potential genetic gain for backward (parent) and forward (ortet) selection are discussed.