The effect of Sitophilus zeamais infestation was evaluated on 10 maize varieties, comprising nine Quality Protein Maize (QPM) varieties (SAMMAZ 14, SAMMAZ 17, SAMMAZ 19, SAMMAZ 32, SAMMAZ 33, SAMMAZ 36, SAMMAZ 37, FLINT-Q and DENT-Q) and one non-QPM variety (SAMMAZ 20) which served as check. The experiment was conducted during two seasons; cold-dry and wet seasons (October - December, 2012 and June - August, 2013) respectively. The maize varieties were infested with ten pairs of newly emerged S. zeamais in seperate kilner jars containing 100 g of each maize variety. The number of F1 and F2 progeny, percentage damage, percentage weight loss, percentage germination and effect of kernel hardness were evaluated for each maize variety. The essential amino acid (tryptophan) and the protein contents of the maize varieties were determined before and after infestation with S. zeamais to determine the amount of losses incurred as a result of feeding by S. zeamais. The result from combined analysis of the two trials showed that at 45 days after infestation with S. zeamais, FLINT-Q (24.63) was the most susceptible variety with the highest mean number of F1 progeny while SAMMAZ 17 (12.63) had the least amongst the QPM varieties. At 90 days after infestation with S. zeamais, DENT-Q (51.63) had the highest mean number of F2 progeny whereas SAMMAZ 17 (19.25) had the least. The highest mean number of damaged grains with emergent holes were observed in FLINT-Q (36.50) followed by DENT-Q (34.88). The highest weight loss among the QPM varieties was also observed in FLINT-Q (7.78) followed by DENT-Q (7.59). The germination test conducted after infestation of the maize varieties indicated that SAMMAZ 14 (75 %) had the highest mean number of viable seeds amongst the QPM varieties, whereas DENT-Q (12.50 %) and FLINTQ (12.50 %) had the least. A maximum reduction in tryptophan as a result of feeding by S. zeamais was found in FLINT-Q (42.86 %) which decreased from an initial value of 0.07 % to 0.04 %. Maximum losses in fraction I (albumin/globulin) proteins were observed in DENT-Q viii (59.68 %) which decreased from an initial value of 0.62 % to 0.25 %. The maximum reduction in the amount of fraction II (zein) protein was observed in DENT-Q (55.36 %) which decreased from an initial value of 0.56 % to 0.25 %. The highest reduction in fraction III (glutelin) protein was in the variety SAMMAZ 19 (59.26 %) which decreased drastically from 0.81 % to 0.33 % at 12 weeks of storage. Minimum reductions in tryptophan (11.11 %), zein (22.22 %) and glutelin (43.85 %) proteins amongst the QPM varieties were observed in SAMMAZ 17 which decreased from 0.09 % to 0.08 %, 0.72 % to 0.56 % and 0.57 % to 0.32 % respectively. The results on the determination of grain hardness showed that SAMMAZ 17 appeared to be relatively harder than all the other QPM varieties. It can therefore be concluded that SAMMAZ 17 variety with relatively hard kernel is the most tolerant variety to S. zeamais infestation which can be stored for 90 days with minimum insect infestation and reduction in protein contents.