Cassava root was fermented with yeast, urea and di-ammonium phosphate (DAP) to determine the degree of conversion of crude to true protein. A completely randomized design (CRD) was used with 6 treatments arranged as a 2*3 factorial with four replications. The treatments were: root processing: steamed and not steamed; DAP: 0, 1 and 2% of the substrate DM. The fermentation was over 14 days with samples taken for determination of true and crude protein at 0, 3, 7 and 14 days. The true protein in cassava root increased with a curvilinear trend (R² = 0.99) from 2.4 to 6.51% in DM as the fermentation time increased from zero to 14 days; the ratio of true to crude protein increased from 0.22 to 0.63 over the same period. Increasing the proportion of DAP from zero to 2% of the substrate DM increased the true protein from 5.57 to 7.29% in DM after 14 days of fermentation. Steaming the cassava root prior to fermentation improved slightly (p=0.17) the conversion of crude to true protein.