Pharmacovigilance (PV) is the science and activities relating to the detection, assessment, understanding, and prevention of adverse effects or any other medicine/vaccine related problem. It is the pharmaceutical science that deals with the "collection, detection, assessment, monitoring, and prevention" of adverse effects with pharmaceutical products. The term "pharmacovigilance" comes from the Greek word "pharmakon" meaning drug and the Latin word "vigilare" meaning to keep watch.

Pharmacovigilance is concerned with identifying the hazards associated with pharmaceutical products and minimizing the risk of any harm that may come to patients. It is important to understand the unique terminology used in drug safety, which is defined by the European Medicines Agency in its Guideline on good pharmacovigilance practices (GVP) .

Pharmacovigilance is a critical component of the pharmaceutical industry and is essential for ensuring the safety and efficacy of medicines and vaccines. Companies must conduct a comprehensive drug safety and pharmacovigilance audit to assess their compliance with worldwide laws, regulations, and guidance. The World Health Organization (WHO) Pharmacovigilance team produces reliable, balanced information on the benefits and risks of medicines and vaccines, which enhances people’s care and safety.

In summary, pharmacovigilance is a science and activity that deals with the detection, assessment, understanding, and prevention of adverse effects or any other medicine/vaccine related problem. It is essential for ensuring the safety and efficacy of medicines and vaccines, and companies must conduct a comprehensive drug safety and pharmacovigilance audit to assess their compliance with worldwide laws, regulations, and guidance.