In the era of advancements in modern science, there is easy availability of good allopathic management options. Besides the beneficial effects, these high potency medicines produce many side effects to other tissues of human body. Therefore the current review article was summarized to identify the medicinal values and importance of Allium cepa (onions) in light of available old and latest researches. Due to its easy availability at homes, it can well be used as a preventive one for many disorders. Raw form of onion when used in specific recommended daily dose, can prevent a human body form many cardiovascular, gastrointestinal, haematological and malignant disorders.