The aim of this study was to produce xylose from tobacco stalk and conversion of xylose to xylitol production by Candida tropicalis. Xylitol is a five-carbon sugar alcohol. Tobacco stalk was hydrolyzed with dilute sulphuric acid to extract xylose. Fermentation ofhydrolysate was performed by Candida tropicalis. The hydrolysate, oxygen and inoculum concentration were optimized for the production of xylitol with high yield. Under the optimum conditions, the hydrolysate was fermented to xylitol with 59% yield and 0.18 g/l-hr volumetric production rate.