A review with 132 references. Several kinds of anxiolytic and hypnotic drugs are currently available on the market. Although BZDs are surely the most frequently prescribed among them, several chemically unrelated compounds have been commercialised, which can provide similar or even higher efficacy and tolerability. These drugs can prove useful for patients who are non-responder or intolerant to benzodiazepine treatment, thus giving broader therapeutic options to the clinician. The most important studies on the metabolic characteristics of several non-benzodiazepine anxiolytics and hypnotics are reported and briefly discussed in this review; moreover, the analytical methods related to these studies are also described and commented upon and their characteristics are highlighted. Finally, an update is included on recent (2007-2010) metabolism and pharmacokinetic studies on benzodiazepines. A monograph is included for each of the following drugs: zolpidem, zaleplon, zopiclone, ramelteon, buspirone and tandospirone; updates are included for the following benzodiazepines: alprazolam, bromazepam, diazepam, flunitrazepam, lorazepam, midazolam, oxazepam and triazolam.