The effect of some fermentation variables (temperature, relative humidity and duration of fermentation) on the fermentation of grated cassava mash for gari production was studied. The proximate composition, functional, chemical and pasting properties were determined using standard analytical methods. The sample fermented at 40OC, 85% relative humidity and 96h (sample 12) had the highest values for protein (2.11%), ash (2.17%) and swelling index (3.62 ml/ml). These values were significantly different (p< 0.05) from the values obtained from the other samples. The HCN content of sample 12 was also very low (4.77 mg/kg) and was not significant different (p> 0.05) from the least value obtained in the study (4.31 mg/kg). It also had the lowest pH value at the end of fermentation of the mash. The length of fermentation was observed to have the most significant effect on most of the parameters monitored while temperature had the least effect. Fermentation of grated cassava mash at 40OC, 85% relative humidity and for 96h will therefore give gari with higher protein content, low HCN and good eating quality.