Phospholipase D (PLD) has important physiological roles in mammalian cells and also acts as a virulence factor of some bacteria besides being an important component of arachnids venom. The frontier for PLD drug studies is to recognize the diversity within the PLD superfamily and try to capitalize on chemical similarities and recognize differences to develop the next generation of potent effective in vivo inhibitors. PLD from Streptomyces chromofuscus is a well-characterized member of non-HKD-PLDs enzymes. Like mammalian superfamily PLD members, non-HKD-PLDs have been the focus of several studies due to their activity in cellular signaling processes and release of bioactive signaling molecules. N-acyl phosphatidylethanolamine-PLD is a membrane-bound protein, localized mainly to the intracellular microsomal membranes. Autotaxin is another important mammalian non-HKDPLD, which has attracted attention as a potential target for drugs. In contrast, “Non-HKD motif” PLD inhibitors are still in the developing stages.