Abstract Myristoylation, the N-terminal attachment of a myristoyl lipid anchor to a glycine residue, can reversibly direct protein–membrane and protein–protein interactions. Apart from two entomopoxviruses, viruses and bacteria usually lack the enzyme N-myristoyltransferase (NMT) that is required for this modification, and their proteins are consequently processed by NMTs of their eukaryotic hosts. This review gives an overview of the multiplicity of viral and the few known bacterial proteins that can undergo glycine myristoylation. In particular, we discuss the role of the myristoyl anchor in viral entry into host cells, in retroviral proteins and in the envelopment of large DNA viruses. We review evidence for myristoylation in arena- and flaviviruses as well as bacterial proteins after their secretion into eukaryotic host cells.