Lactuca L. genus belongs to the Asteraceae family, and has an economic and medicinal importance. Lactuca L. genus is divided into several sections which are widely distributed throughout different ecological and geographical regions. The genus comprises numerous species that comprise major vegetable crops with highly agronomic traits. This book reviews the applications of biochemical and molecular markers for assessing the genetic variability, phylogenetic relationships and taxonomy of Lactuca germplasm in order to provide a recent platform for crop improvement. This book is of interest to Lactuca breeders, researchers, students, and scientists.