The impact of deficit irrigation during berry development on Merlot wine volatile composition was investigated in this study. Own-rooted Merlot vines grown in a commercial vineyard in Idaho were supplied with 100 or 35% of their estimated crop evapotranspiration needs throughout the berry development. Wines were produced from those grapes from the 2002, 2003, and 2004 growing seasons. Volatile compounds in the wines were analyzed using the stir bar sorptive extraction-gas chromatography-mass spectrometry technique. The results demonstrated that despite vintage differences in volatile composition, in each of 3 years of this study, deficit irrigation during berry development had a consistent effect on wine volatile composition. Wine produced from deficit-irrigated vines had increased amounts of vitispiranes, beta-damascenone, guaiacol, 4-methylguaiacol, 4-ethylguaiacol, and 4-vinylguaiacol relative to wine produced from well-watered vines. Deficit irrigation had no effect on the concentrations of other measured volatiles such as esters and terpenes.