The objective of this work was to determine biomass production and nutritional efficiency in three eucalyptus genotypes in the Pampa Biome. For determination of biomass and nutritional characterization, nine medium trees per genotype were sampled, separated in the components leaf, branch, bark, wood and root. The nutritional efficiency of the biomass components was determined using the biological utilization coefficient (BUC). The highest biomass production and mean annual increment were observed in the Eucalyptus urograndis hybrid with 158 Mg ha-1 and 47.2 m³ ha-1, followed by Eucalyptus grandis with 137 Mg ha-1 and 39.7 m³ ha-1 and Eucalyptus dunnii with 122 Mg ha-1 and 23.2 m³ ha-1. For wood, the best nutritional efficiency was provided by Eucalytpus urograndis for P, Ca, and Mn, followed by Eucalytpus grandis for N and Mg, and Eucalytpus dunnii for K.