A prospective observational study was conducted over a period of 5 months enrolling 100 cancerpatientsaged from 18 years to 70 years. Patients with a diagnosis of CIN who received G-CSF were included. Patients were followed up for 15 days. Adverse events (AEs) were graded according to US National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE) version 5.0. The system organ class and preferred term of Medical Dictionary for Regulatory Activities (MedDRA) were used for reporting the AEs. Causality assessment was done by using the WHO-Uppsala Monitoring Centre scale.