Psychiatric pharmacogenomics is a relatively young field of clinical practice, focused on the identification of genetic profiles determining varieties of metabolic patterns that, in turn, assist in the choice of appropriate medications and their corresponding doses. In psychiatry, the mood disorders area has been the most active in trying to advance knowledge and expertise in pharmacogenomics. The cytochrome P450 system (particularly 2D6 and 2C19 enzymes and their respective codifying genes) and, more recently, serotonin transporter and receptor gene tests are among the most utilised and promising. In spite of encouraging findings, however, there are still many questions related to preciseness, scope, ethnic variations, diagnostic implications, 'non-biological' factors, and ethic considerations. The need of algorithms, follow-up studies, and assessment of financial impact, all listed here, require continuous and systematic research. It will not only add to the excitement of pharmacogenomics, but also to the creation of cogent evidence of its benefits.