Psychology is full of excellent discoveries but also dangerous myths, frauds and urban legends. Many of the latter are taught at universities and are popular among psychologists and psychotherapeutists. Some of such pseudo theories are promoted in the field of self-help business or psychotherapy, e.g. the belief in the power of positive thinking, the conviction that early childhood experiences determine who we become as adults or assumption that people project key aspects of their personalities onto ambiguous stimuli like inkblots etc. Most of them create real harm for physically or mentally ill people. This lecture will present psychology’s most dangerous myths and the empirical evidence to show their real value as well as author’s suggestions how to overcome them.