Turmeric (Curcuma longa L.) is used since ancient times in Ayurvedic and Traditional Chinese Medicine. Because of its wide uses it is frequent subject of research. Official herbal drug is produced from the turmeric rhizome and its monograph exists in European Pharmacopoeia. Active ingredients of this plant are curcuminoids (curcumin, bisdemethoxycurcumin, demethoxycurcumin). Actually, curcuminoids are the subjects of ongoing clinical trials. The efficacy of curcumin on osteoarthritis, inflammation, oxidative stress, psoriasis, kidney disease and gingivitis is being investigated because of their antiinflammatory and antioxidant properties. In almost all trials there has been positive effect of curcumin. Curcumin can ameliorate quality of life in oncological patients. Efficacy of curcumin on nervous, cardiovascular and gastrointestinal system has been investigated in clinical trials. Curcumin has found to be effective in treatment of inflammatory bowel disease, in improving glucose status in patients with diabetes, lipid status, anxiety and depression. Because of curucmin's low bioavailability, new formulations are developed. Interactions with metabolites of CYP2D6 are found in clinical trials. There is need for further trials to confirm therapeutic effects of curcumin and its analogues.