Natural products derived from plants for the treatment of diseases have proved that nature stands a golden mark to show the relationship between the interrelationship between man and his environment. The researches and utilization of herbal medicine in the treatment of diseases increases every day. Before the development and civilization by the British in Nigeria, medicinal plants are believed traditionally to be a therapeutic agent for the treatment of diseases such as typhoid, cholera, measles, gonorrhea. However, the knowledge of herbal medicines for treatment of diseases is confined to mostly the practicing herbalists or plant scientists with the belief that herbal medicines will lose their potency if revealed to other people. Although some herbs may have medicinal values, sometimes the medicinal preparation inflicts certain side effects. In view of this, the present study focuses on the knowledge on medicinal uses of plants and the scientific investigation to confirm their medicinal values.