During the 2018–2019 agricultural season, in the town of Choclococha, province of Acobamba—Huancavelica, located at 3440 m above sea level, hail damage was simulated 90 days after planting to evaluate the effects on the yield of amylaceous corn under rainfed conditions. A randomized block design with 7 treatments was used: T1 (no defoliation, Control), T2 (defoliation in 25% of the laminae of each leaf), T3 (defoliation in 50% of the laminae of each leaf); T4 (defoliation in 75% of the laminae of each leaf), T5 (defoliation in 100% of the laminae of each leaf), T6 (total tearing of the laminae of the leaf) and T7 (total tearing of the laminae and rib break-age); all in triplicate. A significant effect was found in the components of corn yield (p < 0.05), except for plant height, at 120 days after planting. The decrease in dry grain yield ranged from 13.53 to 61% with respect to the witness treatment. A significant negative linear relationship was found between the percentage of defoliation and the number (90.66%) and weight (90.25%) of grains per ear, and yield (90.25%). The results would allow estimates to make coherent decisions to compensate for agricultural insurance and the implementation of policies related to food security.