The impact of pH conditions (4, 6, and 8) during modification by dry heated octenyl succinic anhydride on physicochemical, pasting and rheological properties of sorghum starch was studied. Degree of substitution and reaction efficiency values of modified starches varied from 0.013 to 0.021 and 54.6 to 88.2%, respectively, the highest values were observed for starch modified at pH 8. Amylose content of modified starches decreased as compared to native starch. Swelling power and solubility of starches were observed the highest for starch modified at pH 8 and pH 4, respectively. Peak viscosity of starches varied from 239 to 3,138 mPa s, the highest and the lowest values were observed for starches modified at pH 8 and pH 4, respectively. Modified starches showed lower pasting temperature as compared to native counterpart starch. G' and G'' values of starches during heating ranged from 811 to 1,982 Pa and 108 to 191 Pa, respectively. tan δ values of native and modified starches were less than 1, indicating their elastic nature. G' values of modified starches during frequency sweep measurements were less than native starch. Starch pastes from native and modified starches showed shear thinning behaviour during steady shear measurements.