This study investigates aluminum (Al³⁺) tolerance in 150 maize (Zea mays L.) inbred lines under hydroponic conditions. Aluminum toxicity is a major constraint on maize production in acid soils, particularly in tropical regions. The inbred lines were screened in nutrient solutions with and without aluminum stress (222 µM Al³⁺) to assess root length and categorize genotypes as tolerant, moderately tolerant, or susceptible. Supplementary figures show the hydroponic setup and visual differences in seedling root growth, while supplementary tables include detailed pedigree information and root length data. The findings support breeding efforts aimed at improving aluminum stress tolerance in maize.