Amblyomma americantim (L.) the lone star tick, and Amblyomma maculatum Koch, the Gulf Coast tick, are pests of cattle found throughout the southern United States. Several studies have been conducted measuring the susceptibility of Hereford, Brahman, and Brahman-cross cattle to infestations of these Amblyomma ticks. Differences were observed in the numbers of ticks attaching and tick fecundity between susceptible Herefords and Brahman breed cattle, and in host weight gain differences and blood composition. Generally, infested Hereford cattle had higher tick numbers and were more prone to weight gain losses and alterations in blood composition than Brahman breed cattle. Additional studies are discussed that specifically address host immune response to infestation by Amblyomma ticks.