The estimation of RBC plays a crucial role in medical diagnosis and pathological study. The main objective of this system is to detect and estimate the number of red blood cells present in the blood smear sample image. The process is initiated by image acquisition and image enhancement process. Morphological operations are applied on the blood image followed by RBC counting and WBC counting. The primary goal of the proposed system is to detect and count all the blood cells and then count RBC including the overlapping ones in the blood smear image .