Corn or maize (Zea mays L.) is one of the most important cereal crops after wheat and rice. It used for several purposes such as human consumption, livestock and poultry feed, manufacturing starch and cooking oils and it also grown for fodder and silage. Corn is susceptible to drought stress during flowering stages, but it becomes less sensitive as reproduction progress. Drought stress can be reduced yield of corn by 50-70% and 21-47% if it happens during silking and grain filling stages, respectively. Tolerant genotypes of corn were characterized by having shorter ASI, higher number of ears/plant and higher number of kernels/row than susceptible ones. The present work will discuss some of the problems faced by corn breeder in the choice of experimental design, data handling and methods of assessment of drought tolerance, as well as the choice of appropriate breeding method for the development of drought-tolerant genotypes.