: To determine the endometrial Biopsy In Primary Infertility Patients Methods: A prospective study was conducted in the Department of obstetrics and gynaecology, VIMS, Pawapuri, Nalanda, Bihar, India, India for 1 year. A total of 100 endometrial samples of patients having primary infertility were taken for histopathological evaluation. The endometrial samples were consisted of 95 endometrial biopsy and 5 curettage material. This was grossly greyish white to greyish brown in color. Material was immediately placed in fixative fallowed by routinely processed and paraffin section of 5 -6 micron, using hematoxylin and eosin were prepared and studied microscopically. Results: Out of 100 patients, out of which 33 samples (33%) showed proliferative phase, suggestive of an ovulatory cycle where sparse narrow and straight endometrial glands lined by low coloumnar cells embedded in loose stroma of spindle shaped cells in 22 section, while in 3 sections, endometrial glands were more elongated and lined by tall columnar cells, with stromal edema. Remaining 8 sections showed tortuous endometrial glands lined by pseudo stratified epithelium with compact stroma and slightly enlarged stromal cells. Irregular proliferative endometrium was seen in 9 sections (9%) where irregularly shaped enlarged glands interspersed among normal proliferative glands resulting in dyssynchronous development of endometrium. Simple hyperplasia was seen in 5 (5%) cases where section shows cystically dilated proliferating glands of varying size, lined by tall coloumnar cells with many clear cells, while stroma was dense and compact with stromal cells having scant cytoplasm. Conclusion: In infertility, histomorphological study of endometrium not only shows the hormonal response of endometrium but also gives additional information about the local factors of endometrium concerning atrophy, hyperplasia, specific or nonspecific infections and malignancy.