Background: Neonates are expected to have weight loss in the first few days of life. Many factors are considered to affect newborn weight loss such as breastfeeding adequacy, maternal parity, intravenous fluids administered during labor, and environmental factors. Most of the studies have yielded variable results. The primary objective of this study was to assess the pattern of newborn weight loss in initial 72 h after birth and the factors affecting it. The secondary objective was to assess the impact of initial weight loss on neonatal jaundice beyond 72 h and regaining birth weight at the 10(th) day of life. Materials and Methods: A study was carried out on 250 term exclusively breastfed newborn babies. Neonates were weighed initially at birth and then regularly at 12 hourly intervals for 72 h. Data pertaining to various maternal factors affecting neonatal weight loss, birth weight of newborns, and adequacy of breastfeeding were recorded. The weight of the neonates on the 10(th) day was also recorded. Results: About 79.2% of babies lost 5%u10% of birth weight and 12.8% of babies lost more than 10%. The maximum weight loss occurred between 60 and 72 h of life. The mean (standard deviation [SD]) percentage of weight loss in babies with inadequate breastfeeding was 9.01 (2.58) compared to 7.31 (1.82) in the adequately breastfed babies (P < 0.001). The mean (SD) percentage of weight loss in babies born to primipara was 8.31 (1.77) and in multipara it was 7.51 (2.43) (P = 0.005). Neonates who developed significant jaundice had a mean (SD) percentage weight loss of 9.87 (3.40) compared to the rest in whom it was 7.59 (1.92) (P < 0.001). In the subgroup of babies who lost 10% of birth weight at 72 h, 88.2% did not regain birth weight on day 10 of life as compared to 55% of babies in the subgroup with weight loss <10% (P < 0.003). Conclusion: Regular monitoring of weight in exclusively breastfed babies is potentially useful. Particular attention may need to be given to primipara mothers and babies who lose more than 10% weight by 72 h.