Physicians and pharmacists increasingly recognize that pharmacogenomics (PGx)-informed prescribing and dispensing improves both the efficacy and safety of drug treatment. An estimated 15% of the medicines recently evaluated by the EMA contain PGx information in the label that directly impacts patient treatment and this percentage will increase in the near future. Several randomized controlled trials have shown the clinical utility of single drug–gene pre-emptive PGx testing. Examples include PGx testing to guide dosing of thiopurines, acenocoumarol and warfarin, and PGx testing to guide drug selection for carbamazepine and abacavir. Interestingly, this gold-standard evidence has focused on individual single gene–drug pair(s). Pre-emptive PGx testing for a panel of relevant pharmacogenes may be even more informative and clinically relevant than testing for individual gene–drug pairs. Reasons for this being threefold. First, PGx test results are static and can, therefore, be utilized lifelong. Second, over the course of their lifespan most patients will likely use multiple drugs of which multiple may benefit from PGx-informed prescribing. Third, actionable PGx variants are highly common in the population and recent studies show that more than 95% of the population carry at least one actionable PGx variant when tested for a panel of six to eight well-recognized pharmacogenes. Indeed, the positive effects of pre-emptive PGx testing for a panel of genes have recently been demonstrated in several small studies. Nevertheless, convincing evidence from well-designed, sufficiently powered prospective studies is needed. To fill this unmet need and to achieve implementation of PGx-guided prescribing in Europe, the Ubiquitous Pharmacogenomics (U-PGx) consortium was founded.