Covalent attachment of myristate occurs on a wide variety of viral and cellular proteins. This modification is often essential for the proper functioning of the modified protein. The myristoylation plays an important role in protein-lipid interactions, which are modulated by the interplay between protein phosphorylation and calmodulin. Myristoylation is also involved in protein-protein interactions. In this review, recent advances in understanding the role of protein myristoylation in both protein-lipid and protein-protein interactions and the regulation of these interactions will be discussed on the basis of the structural studies.