Peptide deformylase (PDF) was originally viewed as unique only to the prokaryotes and lacking from the eukaryotes. In bacteria, PDF is the enzyme that catalyzes the removal of the N-formyl moiety from the initiator methionine residue during protein translation and is essential. Inhibitors that target its reaction mechanism are also potent against bacterial growth. This property makes PDF an attractive novel drug target. Recent genomic sequencing has also revealed PDF homologs in eukaryotes. This book, therefore, provides evidence and insight into two PDF homologs found in the malaria-causing organism, Plasmodium falciparum, and human. Both eukaryotic PDFs are enzymatically active but localized in the cellular organelles and raise the concern of the effectiveness of PDF as an antimicrobial drug target. However, the rational design of a novel class of PDF inhibitors demonstrates specificity toward the bacterial and the eukaryotic counterparts. The evidence and study presented in this book should help shed some light on the forefront of the much needed, novel antimicrobial drug target and discovery field.