Vegetables, which contain minerals and vitamins, are a major source of nutrition for humans, and are negatively impacted by a variety of abiotic stresses, particularly drought. This is a constraint that must be overcome to avoid yield losses while maintaining nutritional and global food security. Generation of drought tolerant vegetable varieties is an important and time-consuming challenge for crop breeders. Though conventional crop breeding methods have been used to their full potential for the development of drought tolerant varieties, their applications are limited in crop improvement due to time lag, environmental dependency, and low efficiency. With the introduction of low-cost advanced next-generation sequencing technology, plant breeders can now better understand the drought stress-tolerance mechanisms and associated genomic regions, thanks to QTL identification and mapping. This chapter will emphasize the importance and current status of QTL mapping in producing drought stress-tolerance crops in the near future.