An experiment was conducted in 1989 to screen Acacia senegal L. Willd provenances collected from within the natural gum belt for high water use efficiency. Thirteen provenances were tested for water use efficiency and consequently 6 out of them were selected for further screening. The selection was based on their performance in the preliminary screening. Both the preliminary and the detailed study revealed that provenances 7, 3 and 11 combine high dry matter production with high water use efficiency. Water use efficiency and dry matter production appears to be negatively correlated with root length density and root/shoot ratios. Provenances 7 which exhibited the highest water use efficiency and dry matter yield had the lowest root/shoot ratio and also a low root length density. Based on these studies provenance 7 can be considered a suitable candidate for introduction into gum-belt of Sudan through for rehabilitation of this region. (author). 5 refs, 1 fig., 3 tabs.