This research work investigates the effect of addition of potassium hydroxide (KOH), an alkali, and lime on the properties of cassava peel ash (CPA) blended cement mortar. Four binder combinations were used, viz; ordinary Portland cement (OPC, control), OPC-CPA blend, OPC-CPA-Lime blend and OPC-CPA-Lime-KOH blend respectively at 10% replacement of OPC with CPA. Properties investigated include strength and durability, measured using sorptivity, water absorption and apparent porosity for mortar specimen cured at 7, 14 and 28 days respectively for each of the binder combinations. The result shows that the OPC-CPA-Lime mortars showed better compressive strength, sorptivity, apparent porosity and water absorption performance than the other mixes. The performance of CPA-Lime blended cement mortar at 10% replacement of OPC with CPA and 4% replacement of CPA with lime compared favorably with OPC mortars in terms of strength and durability and is thus recommended for use in mortars.