Foeniculum vulgare, also known as fennel, is a well-known herb cultivated for its culinary and medicinal applications. Commonly used as a remedy for indigestion, fennel is a perennial plant grown in temperate climates and harvested during the summer and fall. Though side effects associated with the use of foeniculum are rare, women who are pregnant should consume fennel in moderation. Indigenous to the Mediterranean region, foeniculum vulgare is widely cultivated in temperate climates for its leaves and seeds. Fennel leaves are generally harvested during the months leading up to the first frost. Belonging to the parsley family, fennel is a feathery perennial plant that matures to a height of 6 feet (2 m). The delicate, yellow flowers of the foeniculum vulgare are frequently used to accentuate summer, floral bouquets. Since ancient Greece, fennel has been utilized to increase lactation for nursing mothers. Historically, fennel has also been associated with strengthening eyesight and as a treatment for eye conditions, including fatigue, irritation, and infection. The detoxification properties of fennel make it a valuable herb for cleansing the body, promoting weight loss and fighting infection. Traditionally, herbal fennel infusions have been used to treat infections associated with the respiratory system. There can be a rare allergic response induced when an individual consumes the fennel fruit. The volatile oil of fennel and its prepared extracts should only be consumed in minimal doses due to the risk of skin irritation, vomiting, respiratory distress, and seizure. Due to its potential health hazards, fennel oil should never be used as a culinary or self-medication ingredient. Women who are pregnant should avoid using fennel excessively due to its potential estrogenic effects. Compilation of scattered literatures in the form of a book is the Author’s main aim. This book will be very useful for research scholars, scientists and students.