Two widely-used open pollinated maize (Zea mays L.) cultivars from East Africa, Katumani and Kito composites, developed and improved for early maturity, grain yield and drought escape were evaluated for drought tolerance at seedling and flowering stages, and compared with other drought tolerant maize populations. Under seedling-stage, the early maturing cultivars were the most drought tolerant with large biomass accumulation in both stress and non-stress environments. However, root weight and the root: shoot ratio were relatively small. Under drought at flowering, these cultivars flowered early and reached anthesis in 66 days (d) for Katumani and 73 d for Kito, compared to an average of 100 d for the trial. Grain yields were (359 kg ha-1 for Katumani and 679 kg ha-1 for Kito) than the trial average of 1002 kg ha-1 under severe stress. Under well-watered conditions the yields were 3,295 kg ha-1 for Katumani, 4,651 kg ha-1 for Kito compared to the trial average of 5,737 kg ha-1. Low grain yield was associated with a large anthesis-silking interval (ASI) of 28 d in Katumani compared to an average of 18 d for the trial; and strong leaf rolling and high leaf abscisic acid concentration. Katumani and Kito were less stable for yield across water availability environments.