Higher production of xylitol was obtained in the process conducted with CABH supplemented with urea, it was achieved 12.27 g L−1(17.9% more than the xylitol concentration obtained using the control medium). The addition of ammonium sulfate andyeast extract showed no favoring on xylitol production. In fact,instead of increasing xylitol production, it eventually reduced it to around 8%. An Analysis of Variance (ANOVA) and Tukey Tests at 5%level of significance showed no significant difference in the additionof any of the employed nitrogen sources (urea, ammonium sulfateand yeast extract), in the fermentation conducted with the strain K. marxianus CCA510. On the other hand, adding urea improved the production of xylitol in relation to the addition of ammonium sulphate and yeast extract. It was observed that the highest yield of xylitol (0.50 g g−1) was achieved in the medium containing urea as nitrogen