Growth performance and psyllid resistance was studied among nineteen lesser- known Leucaena species/ provenances at Gairo inland plateau, Morogoro, Tanzania. Assessment was done at irregular intervals for survival, root collar diameter and diameter at 30 cm above the ground, height, diameter at breast height, multiple stems production, biomass and psyllid resistance. Final assessment of these tree attributes was done at 37 months after planting, while psyllid resistance was assessed at 9 and 37 months after planting. During the final assessment occasion, height ranged from 2.69 m for L. collinsii Ex. Chiapas to 4.87 m for L. diversifolia Ex. Veracruz. Diameter at breast height (Dbh) ranged from 2.26 cm for L. shannonnii Ex. Chiapas to 4.93 cm for L. diversifolia Ex.Veracruz, while multiple stems production ranged from 2709 stems ha-1 for L. pulverulenta Ex. Tamaulipas to 7135 stems ha-1 for L. leucocephala Ex. Morogoro and untransformed survival ranged from 43.75% for L. pulverulenta Ex. Tamaulipas to 100% for L. diversifolia Ex. Veracruz. Total wood biomass production ranged from 3.74 t/ha for L. shannonnii Ex. Chiapas to 15.61 t/ha for L. diversifolia Ex. Veracruz. The study has shown that species/ provenances differ significantly in survival, diameter, height growth, psyllid resistance, multiple stem production and biomass production. Based on these findings, provenances L. diversifolia Batch (15551), L. diversifolia Ex. Mexico, L. diversifolia Ex. Veracruz and L. pallida Ex. Oaxaca are recommended for Gairo and similar sites. Keywords: Lesser-known Leucaena, survival, growth, biomass production and psyllid resistance No Abstract. Southern African Forestry Journal Vol. 208, 2006: 53-6