The goal of this research project was to assess the effects of an intervention programme based on theatrical improvisation in three different groups of Asperger Syndrome adolescents. It was organised around 2 single individual case studies and one small group, which included 11 participants. Study 1: a 14-year-old female adolescent of high sociocultural level within a mainstreamed high-school group. Study 2: a 12-year-old male adolescent of low sociocultural level within a mainstreamed high-school group. Study 3: 9 adolescents, 14-19 years old, enrolled in an Asperger and Autism Association. Three different intervention programmes were implemented. All of them based on theatrical improvisation and focused on spontaneity and imagination. Open-ended questions, diaries and semi-structured interviews were used to assess the programmes' impact. Analyses of the data produced four major themes of balanced importance and several sub-themes: "expression" ("express oneself," "overcoming external judgement"), "creativity" ("spontaneity," "imagination"), "benefits" ("taking risks," "de-stressing," "motivation," "self-esteem"), and "socialisation" ("being accepted," "knowing the other participants," "being part of the group"). These findings indicated that theatrical improvisation can produce positive effects in Asperger Syndrome Adolescents.