The objective of the present study was to evaluate the initial growth of Khaya senegalensis plants under water deficit. The work was carried out at Ipameri, Goias on a bench in full sun following the completely randomized experimental design with six treatments and six replications. 120-day-old mahogany plants (Khaya senegalensis) grown in eight-liter pots were subjected to six treatments for 12 days (plants irrigated daily with 100, 80, 60, 40, 20 and 0% of evapotranspiration) with six replications. At 132 days after emergence, the plants were assessed for: plant height, stem diameter, number of leaves, foliar area, daily transpiration, relative water content, total chlorophylls and carotenoids, leaf, stem and root mass ratios, and total biomass. The data were submitted to F-test and, when significant, to regression test at 5% probability. High stomatal control, reduced transpiration, low leaf concentration of total chlorophylls and increased root system growth to the detriment of the shoot growth indicate that Khaya senegalensis is tolerant to moderate water deficit. Key words: Silviculture, wood noble, forest physiology.