Social anxiety has a negative impact on individual’s daily life and disturbs his or hers social adaptation. Socially anxious people are often lonely, have difficulties in meeting new people and communicating with others. Social anxiety can also be a serious obstacle to professional growth and career development, can interfere with obtaining new skills and knowledge. Severe social anxiety is often associated with a variety of disorders, including depression, alcohol and drug addiction, eating disorders. However, social anxiety has a high prevalence among population. In this regard, it is becoming increasingly important to diagnose social anxiety. Therefore, the aim of our study was the validation of two questionnaires measuring social anxiety “Liebowitz Social Anxiety Scale“ and “Fear of Negative Evaluation Scale“. The validation was conducted on 179 people (65 men and 114 women), aged from 18 to 35 years. “Liebowitz Social Anxiety Scale“ measures the degree of anxiety and a tendency to avoidance occurring in various social situations: situations of social interaction and performance situations. «Fear of negative evaluation (brief version)» measures the central construct underlying social anxiety - the fear of negative evaluation. As a result of factor analysis of the data it is demonstrated, that “Liebowitz Social Anxiety Scale“ has three-factor structure. Single-factor structure of the «Fear of Negative Evaluation Scale» is confirmed. It is shown that all the subscale “Liebowitz Social Anxiety Scale“ and “Fear of Negative Evaluation Scale (brief version)“ has good internal consistency, high test-retest reliability and external validity.