The study evaluated the effect of healthcare professionals (HCPs) on knowledge and attitude towards reporting adverse drug reactions (ADRs) in military and paramilitary hospitals in Enugu, Nigeria. The purpose of the study was to determine if the level of knowledge and attitude has any significant effect on reporting ADRs. Data were collected through the use of questionnaires from the healthcare professionals (Doctors, Pharmacists, and Nurses) because of the position they occupy in the implementation of pharmacovigilance procedures. The technique employed in the data analysis is regression and the following results were obtained: the level of knowledge of HCPs on pharmacovigilance had a P- value of 0.027 < 0.05 while HCPs attitude had p-value of 0.010 < 0.05. Hence, the study concludes that knowledge level and attitude significantly affect ADR reporting. The following recommendations were made in line the findings: the need to improve training programs across all strata of HCPs as a means of updating their knowledge of pharmacovigilance and ADR reporting procedures. Similarly, it is important to develop a culture of ADR Reporting amongst healthcare professionals in these hospitals; by raising the recognition of the importance of reporting both tolerable and moderate ADRs as well as previously unknown or severe ADRs, this strategy aims to promote a culture of ADR reporting.