Abstract: Background and Objective: Elevated carbon dioxide (CO2) has the ability to mitigate plant drought stress. Not many studies were done to find the combined effects of drought stress and elevated CO2 on C4 plant growth under low photosynthetic photon flux density (PPFD). In this study, drought mitigating effects of elevated CO2 were assessed on the vegetative growth of maize (Zea mays L.) plants under low PPFD. Materials and Methods: Maize plants were grown in two growth chambers, one maintained at ambient CO2 (435 μmol mol–1) and the other at elevated CO2 (1000 μmol mol–1), conditions under low PPFD. Plants were subjected to three water stress treatments by reducing irrigation: Once every 7 days (SD, control), every 14 days (FD) and every 21 days (TD). Data were collected on chlorophyll content, stomatal and epidermal characteristics and plant vegetative growth (height and girth). Data were analyzed using SPSS and MANOVA. Results: The elevated CO2 in combination with TD water stress treatment, induced higher chlorophyll ‘a’ (6.95 vs 10.93 μg cm–2), chlorophyll ‘b’ (2.63 vs 3.80 μg cm–2) and total chlorophyll content (14.73 vs 9.38 μg cm–2) compared to TD water stress treatment in ambient CO2. The longest and the widest stomata were recorded under elevated CO2 conditions in the FD (39.40±1.56 cm) and TD (26.63±2.29 cm), respectively. Further, the highest stomatal density was observed in TD under elevated CO2 (151 stomata/mm2). The combination of elevated CO2 and FD water stress treatment registered the tallest (mean = 112.80 cm) and thickest (mean = 2.97 cm) maize plants in the experiment. Conclusion: Elevated CO2 increased vegetative growth of maize plants especially under FD water stress treatment. The low PPFD was not a constraint for elevated CO2 in mitigating the drought stress.