In the present study, the Casson fluid flow over a vertical porous surface with chemical reaction is investigated. The governing partial differential equations are converted into ordinary differential equations by using similarity transformations. The reduced system of equations is then solved using an implicit FDM known as the Keller Box method. The velocity and concentration profiles are examined for various changes in the different governing parameters like the Casson parameter, suction parameter, Grash of number, and the Schmidt number.