The process of drug discovery and development involves a synchronous activities of both preclinical toxicity testing methods and adverse drug reaction monitoring at clinical set ups. In clinical phases of drug development, pharmacovigilance guarantee the safety of pharmaceutical usage by identifying and evaluating adverse drug reactions (ADRs). An appropriate and well-structured ADR monitoring could help patient safety by determining the degree and causation of ADRs by certain drugs. Recently, the ADR detection and assessment are being improved by new instruments, algorithms, scientific and regulatory developments. Early detection and proactive management of ADRs can help to mitigate potential risks to patient safety and ensure the success of drug development endeavours.