An investigation was taken up to study the anatomical differences between the insect pest resistant and susceptible genotypes of cotton. It was observed that the resistant genotypes (JK-119, JK-345-3-3 and JK-276-4) registered a lesser thickness of the leaves, diameter of the petioles, midribs and the stem tips as compared to the susceptible genotypes (Sharada, DCH-32 and Laxmi). Cell density of the tissues of resistant genotypes was higher than the susceptible ones suggesting the insect pest resistance to be positively correlated with the genotypes possessing compact tissues. Thus, the anatomical parameters of a genotype could supplement for the host-plant resistance mechanisms