Apart from low soil fertility, drought is the factor most responsible for limiting maize productivity in sub-Saharan Africa, affecting 44% of the arable land. Selection for drought-tolerant maize genotypes has been centred on using conventional breeding methods. Marker-assisted selection (MAS) through the use of DNA markers may increase the efficiency of selecting drought-tolerant genotypes. Over the last decade, the International Maize and Wheat Improvement Center (CIMMYT) has mapped quantitative trait loci (QTL) in several mapping populations across several environments. To evaluate the efficiency of MAS based on a consensus map, four populations (CML312/NAW, CML440/Compe, CML441/CML444, K64R/CML444) were developed for this study, each comprising 500–600 F2 plants. Fifty of these were grown under drought conditions to establish which parent contributed more to the better drought-tolerant allele at the locations of the stable QTL. From each of the populations (of 500–600 F2 families), CIMMYT scientists in Mexico selected 100 families based on the presence or absence of favourable alleles at the locations of stable QTL. For this study, contrasting families were test crossed to two single-cross testers from the opposite heterotic group: Tester A = CML312/CML442 for CML 441/CML444 and K64R/CML444; Tester B = CML395/CML444 for COMPE/CML440 and NAW/CML312. The test crosses were evaluated under low and optimal nitrogen, and under drought and well-watered conditions. The trials were laid out using alpha-lattice designs with two replicates planted at six locations in Malawi and Zimbabwe. Data collected included days to pollen shed and flowering, plant and ear height, leaf senescence, disease score for leaf blight and rust, and gray leaf spot, ear number, ear weight, grain weight, grain texture, moisture content and 100-grain weight. Preliminary results will be presented to assess the efficiency of marker-assisted selection in these populations and environments in the context of test-cross evaluation, as a tool for selecting drought-tolerant maize genotypes.