Background and objectives: Unnecessary early antibiotic exposure is deleterious, it may induce the selection of multi-drug-resistant organisms. The objective of this project was to decrease antibiotic exposure of newborns admitted to the neonatal intensive care unit at Hospital Cayetano Heredia, a level 3 unit in Lima, Peru. Methods: Quality improvement project in which we implemented an antibiotic stewardship program for early onset sepsis in the neonatal intensive care unit. Primary outcome measure was antibiotic usage rate, total number of days infants were exposed to antibacterial agents divided by 1000 patient-days. Results: Antibiotic usage rate declined from 291/1000 patient-days to 82/1000 patient-days during the last months of 2020, representing a total decrease of 65.1%. Conclusions: Antibiotic stewardship for early-onset sepsis implemented in a perinatal center like ours is effective, appears to be safe and results in a sustained and significant decrease in the use of antibiotics for early-onset sepsis.