The present study deals with sub-chronic oral toxicity studies in rodents of micronized domperidone matrix drug formulation. The matrix tablet of domperidone was formulated by using different polymers. After the completion of the formulation the matrix tablets the tablets were crushed into powder and a homogeneous suspension was prepared. The suspension was administered to rats at different dosages according to the study plan. During the studies animals’ weight were taken at periodically. After 28th day of study period the animal’s blood was collected for pathological and biological analysis. At the termination of study, all the animals were sacrificed and vital organs were taken out for autopsy studies. After the thorough studies the results shows that that the micronized formulation did not produce any significant toxicity in rodents.