Protein acylation is a post-translational modification that has seized much attention in the last few years. Depending on the nature of the fatty acid added, protein acylation can take the form of palmitoylation, myristoylation, or prenylation. Palmitoylation has been implicated in the modification of several different proteins and is particularly prevalent in G-protein coupled receptors and their cognate G-proteins, where it is thought to have an important regulatory function. Given that palmitoylation of these proteins is a dynamic phenomenon in which turnover rate is modulated by agonist activation, it is thought to be implicated in processes such as receptor phosphorylation and desensitization as well as in G-protein membrane translocation. A better understanding of the regulation of signal transduction mediated by G-protein coupled receptors will require the identification and characterization of those enzymes implicated in the palmitoylation and depalmitoylation process of this large class of receptors and their signalling allies.