Drought stress has a significant negative impact on plant growth, yield and quality of crop plants, particularly under current climate change. Therefore, improving drought tolerance in field crops is essential to increase sustains productivity particularly in arid and semi-arid regions in the Mediterranean basin. There are various selection criteria associated with drought tolerance could be exploited in selecting drought-tolerant genotypes. Combining morpho-physiological and biochemical traits can provide a more completed model of gene-to-phenotype relationships and genotype-by-environment interactions. Integration of recent advances breeding methods as quantitative trait loci, marker-assisted selection and genetic engineering technique with classic plant breeding helps significantly in developing drought-tolerant genotypes accurately and rapidly. This chapter also addresses to genetic diversity among genotypes, related traits to drought tolerance, genetic behavior, breeding efforts and biotechnology in rice, maize, barley and sunflower.