Quantitative sensory testing comprises methods that document alterations and reorganization of the nociceptive system. Measuring an abnormal result in a chronic pain patient may provide us with the information that the underlying pain pathways somehow must be altered. An essential question is whether this information can be linked to drug efficacy in a mechanism-based treatment approach. A further important question is whether assessing genetic polymorphisms can explain different drug effects and hence help selecting the appropriate therapeutic strategy for individual patients.