A double blind trial, was designed, in which 118 patients undergoing the removal of impacted wisdom teeth were randomly divided into the following groups; 41 patients received Metronidazole, 39 patients received Arnica Montana, 38 patients received the placebo. Metronidazole was more effective in pain control than Arnica (p<0.001) and placebo (p<0.01). It prevented swelling better than Arnica (p<0.01) and placebo (p<0.05) and was more effective in promoting healing than Arnica (p<0.01) and placebo (p<0.01), but had no effect on trismus when compared with Arnica (p>0.1) and placebo (p>0.02). Arnica Montana appeared to give rise to greater pain than placebo (p<0.05) and caused more swelling than the placebo (p<0.01).