This study was carried out to investigate the effect of hydrochloric acid on the dissolution of titanium present in ilmenite ore. The X-ray diffraction characterization of the ore reveals that it consists of iron, titanium and silicon oxide phases. Alkaline pretreatment of Nigeria ilmenite ore was carried out using 1.5M of sodium hydroxide. Leaching of the pretreated Nigeria ilemnite was carried out using hydrochloric acid (HCl) concentration of 2, 4 and 6moles, leaching temperature of 50,85,100, fixed leaching time of 150 minutes, fixed particle size of <0.5μm and fixed solid-liquid ratio of 0.1g/ml. Leaching of ilmenite ore with hydrochloric acid, the optimum leaching condition for ilmenite ore was at 6 M hydrochloric acid, leaching time of 150 minutes, solid-liquid ratio of 0.1gm/l, particle size of <0.5μm and leaching time of 85 °C, under these conditions, the optimum dissolution of Ti 81.01% was obtained.