Background: Placenta is a vital organ for maintaining pregnancy and promoting normal fetal development and function. It is the only organ in the body which is derived from two separate individuals, the mother and the fetus. It is responsible for their aspiratory, nutritional, excretory, endocrine and the immunological functions of the fetus. Birth weight is an important determinant of child survival, healthy growth and Development. Aim: to determine the morphometric of placenta in relation to birth weight of full term newborns in Anugrah Narayan Magadh Medical College and Hospital, Gaya, Bihar, India Materials and methods: The present study was the conducted in Department of Anatomy. Total 120 discarded placenta were collected at random from deliveries (both vaginal and caesarian) conducted Anugrah Narayan Magadh Medical College and Hospital, Gaya, Bihar, India, for 15 months. 60 out of the 120 placentawere from controls (birth weight > 2500gms) and 60 from low birth weight deliveries (birth weight <2500gms). In the collected placenta, the weight, volume, diameter and thickness of placenta were measured. Results: Out of 120 placentas which were equally distributed between two groups, group A which included placenta of normal birthweight newborns and groupBwhich included placenta oflow birth weight newborns. The 68.33% of placenta had birth weight 400-500 gms and followed by 31.67% >500 gms in group A, and 63.33% of placenta had birth weight <400 gms in group B. 41.67% of placenta had volume 401-499 ml and followed by 31.67% of placenta had volume ≤ 400 ml in group A and 78.33% of placenta had ≤ 400 ml volume in group B. The mean placental weight was 458.97±32.04gms in normal birth weight group and 373.88±47.23 gms in the low birth weight group. The mean placental diameter was 19.88±0.93cm in normal birth weight group and 16.96±2.32cm in the low birth weight group. The mean placental thickness was 1.85±0.32cm in normal birth weight group and 1.73±0.22cm in the low birthweight group. Themean placental volume in the normal birth weight group was 442.09± 41.12ml and in the lowbirthweight group itwas 373.88±47.23 ml. Conclusion: we concluded that the values of placental weight, volume were lower in small for gestational age group babies as compared to full term normal group babies. The volume of the placenta is directly proportional to the birth weight of the baby.