Ever since we know that the dissimilarities of medications are influenced by the in vivo process of the body, including absorption, distribution, metabolization, and excretion, great attentions have been paid on pharmacogenomic issues, trying to figure out the underlying mechanisms of drug response deviations. Personalized regimens based on pharmacogenomic testing increased the efficacy and decreased the toxicity of certain drugs; therefore, correct understandings and utilizations of gene screening are of great benefits in rational medication usages. This chapter mainly introduced the pharmacogenetic information of some anti-infective agents, hoping to provide some tips for clinicians and other medical care providers.