Volatiles from plants have been used for perfumes and incense since ancient times. Today, the perfume industry incorporates extensive research on plant volatiles. Flavor chemists also study and use volatiles from plants to improve food quality. The vast information accumulated by perfume and flavor chemists forms an excellent base of knowledge for studying plant-insect interactions. The following is an overview on subsequent chapters which discuss some of the latest methods and equipment in sample preparation, analyses and identifications of volatiles from various flowers, leaves, and fruits. Also, activities other than olfactory responses, such as bacterial growth inhibition and increase or decrease of motor activity, are briefly reviewed