Cucurbits include a genetically diverse group of plants and one of the most important and large groups of vegetables growing worldwide, including cucumber, squash, gourd, pumpkin, melon and watermelon. The book of the XII Eucarpia Meeting on Cucurbit Genetics and Breeding, provides the abstracts of the works presented orally or by poster during this virtual meeting. The book will allow the readers to find out the most recent research activities carried out by researchers specialized in these species. The book is divided into chapters corresponding to the sessions celebrated in this meeting. It delivers new information about evolution, diversity and distribution of those species; explores the new genetic resources for characters of agronomical interest and the breeding and cultural methods used to improve their quality and production facing to both biotic and abiotic stresses; provides the cultural requirements for their optimal production and a large number of diseases, viruses and pests affecting their optimal development; finally, introduces a new and relevant topic which is the influence of the abiotic factors (eg. drought, heat, salinity) on their development. Authors have remarkable experience in cucurbits and/or the different topics herein considered which is a guarantee of its interest.