PURPOSE: To determine the effects of exercise heat-induced two percent dehydration (DEH) and euhydration (EUH) with a six percent carbohydrate-electrolyte solution (CES) compared with placebo EUH (P EUH) on basketball skills in skilled young players. METHODS: Fifteen 12- to 15-yr-old boys underwent three separate 2-h exercise heat exposures (double blind, random order): 2% DEH by limiting fluid intake during exercise in the heat and basketball skill drills, EUH (no net weight change) with a 6% CES, and EUH with a flavored water placebo (P EUH). After recovery, subjects performed an orchestrated sequence of continuous basketball drills designed to simulate a game (12-min quarters + a 10-min halftime). Performance measures and component drills inherent to basketball included various individual and combined shooting percentages (3-point, 15-foot, free-throw shots), sprint (suicides, court widths), lateral movement (zigzags, lane slides), and defensive drill (combining lateral and front-to-back movement) times. RESULTS: Compared with P EUH (53 +/- 11%), combined shooting percentage was impaired by 2% DEH (45 +/- 9%; P = 0.002) and improved by CES intake (60 +/- 8%; P = 0.003). Total sprint times showed a similar effect (83 +/- 10 vs 78 +/- 9 vs 76 +/- 9 s; DEH vs P EUH vs CES; P < 0.001 and P = 0.04, respectively). Total lateral movement times were impaired by 2% DEH (73 +/- 8 vs 68 +/- 8 s; P = 0.001). CES improved total defensive drill times compared with 2% DEH (77 +/- 10 vs 82 +/- 10; P = 0.006). CONCLUSION: Deterioration in basketball skill performance accompanies two percent dehydration in skilled 12- to 15-yr-old basketball players. Additionally, EUH with a 6% CES significantly improves shooting performance and on-court sprinting over EUH with water.