The need to improve the nutritive value of feed materials containing high levels of non-starch polysaccharides (NSPs) such as lignin, cellulose, mannan among others for monogastric feeding has led to interest in solid state fermentation (SSF) in recent years. In this study, the efficacy of SSF to improve nutritive value of mixture of grated cassava roots and palm kernel cake for pig feeding was evaluated using 40 unsexed crossbred (Large White X Nigerian Indigenous) weaner pigs. The pigs were randomly allotted to five treatment groups and fed experimental diets in which the maize in the control diet was partially (50%) or completely replaced with either solid state fermented mixture of grated cassava root and palm kernel cake (FEMCARPP) or a 1:1 blend of cassava meal and palm kernel cake (CSM-PKC). Data was collected weekly on the live-weight, weight gain, feed intake and feed conversion ratio, and efficiency of protein utilization. The pigs on dietary FEMCARPP consumed significantly (p < 0.05) less feed but had superior weight gain and similar feed conversion ratio when compared to the control pigs fed maize based diets. In addition, pigs fed dietary CSM-PKC consumed significantly (p < 0.05) more feed and were less efficient in utilizing their feed. It is therefore concluded that solid state fermentation improved the nutritive value of mixture of grated cassava roots and palm kernel cake for swine feeding. Further research is however needed to extend the study to growing-finisher phase and to understand the physiological mechanism of the improved performance of the piglets on dietary FERMCAPP.