Phenothiazines are the oldest and the largest group of neuroleptic drugs. These compounds are widely used in psychiatry, especially in the treatment of schizophrenia, maniac and delusion disorders. They exhibit valuable antiemetic, antihistaminic and antitussive properties. There have appeared numerous articles for last ten years on new biological properties of phenothiazines, among them anticancer, antibacterial, antiprotozoic, antiviral, antiprionic and multidrug resistance reversal activity. Considering intensive development in the studies on the new activities of phenothiazines it seems to be necessary to organize and clarify the recent knowledge in this field.