Herbal drugs are often used in patients with somatoform disorders yet, the available evidence is limited. The aim of the present short-term study was to evaluate in a pharmaco-clinical trial the additional benefit of butterbur in a fixed herbal drug combination (Ze 185 = 4-combination versus 3-combination without butterbur and placebo) in patients with somatoform disorders.For a 2-week treatment in patients with somatization disorder (F45.0) and undifferentiated somatoform disorder (F45.1), 182 patients were randomized for a 3-arm trial (butterbur root, valerian root, passionflower herb, lemon balm leaf versus valerian root, passionflower herb, lemon balm leaf versus placebo). Anxiety (visual analogue scale - VAS) and depression (Beck's Depression Inventory - BDI) served as primary parameters, Clinical Global Impression (CGI) was a secondary parameter.The 4-combination was significantly superior to the 3-combination and placebo (4-combination > 3-combination > placebo) in all the primary and secondary parameters (PP-population). Analysis of the ITT population confirmed these results. As to safety, no serious adverse events occurred. In total 9 non-serious adverse events were documented but the distribution did not differ significantly between the treatment groups.This herbal preparation (Ze185) showed to be an efficacious and safe short-term treatment in patients with somatoform disorders.