Purpose: Evaluation of The accuracy of Hoffer Q formula for intraocular lens (IOL) power calculation in short and long axial lengths of the eye.     Methods: 100 eyes divided equally into 2 groups: group I (50 eyes) with axial length more than 24.5 and group II( 50 eyes) with axial length more less than 22. Comparison between both groups was done as regards post operative residual refractive error after IOL implantation using Hoffer Q formula.   Results: Insignificant difference between the 2 groups as regard post operative residual refractive error.  In short length eyes, the mean postoperative refractive error with Hoffer Q formula was 0.80 +0.33D. In long eyes, the mean postoperative refractive error was 1.23 +0.70D. The results show that the best performing formula was in short eyes (P = 0.012).   Conclusion: Insignificant difference as regards postoperative residual refractive error between both groups but Hoffer Q formula best performed in short eyes.