IMC tuned PID controller’s present excellent set point tracking but sluggish disturbance elimination, because of introduction of slow process pole introduced by the conventional filter. In many industrial applications setpoint is seldom changed thus elimination of disturbance is important. The paper presents an improved IMC filter cascaded with Controller PID tuned by internal model principle (IMC-PID) for effective elimination of disturbance and healthy operation of non-regular first order process such as processes with no delay. The suggested filter eliminates the slow dominant pole. The present study shows that the recommended IMC filter produces excellent elimination of disturbance irrespective of where the disturbance enters the process and provides acceptable robust performance to model disparity in provisions of maximum sensitivity in comparison with other methods cited in the literature. The advantages of the suggested technique is shown through the simulation study on process by designing the IMC tuned PID controllers to maintain identical robustness in provisions of maximum sensitivity. The integral error criterion is used to estimate the performance. The recommended filter produces excellent response irrespective of nature of the process.