The 5-hydroxytryptamine6 (5-ht6) was one of the most recent additions to the5-HT receptor family, selective antagonists have recently been developed and potentialfunctional roles are now becoming apparent. The high affinity of a wide range ofpsychiatric drugs for the 5-ht6 receptor, together with its almost exclusive expression inthe CNS, being abundant in limbic and cortical regions, has stimulated significantresearch interest. The 5-ht6 receptor appears to regulate glutamatergic and cholinergicneuronal activity, and increasing evidence suggests that it may be involved in the regulationof cognition, feeding and, possibly, affective state and seizures. The current article will review all aspectsof the discovery, genetics, distribution, pharmacology and function of the 5-ht6 receptor. Taken together, thiswealth of information warrants the use of the upper case nomenclature for the 5-ht6 receptor to be approved andits true status recognised.