People with intellectual disability (ID) generally tend to have difficulties expressing their thoughts and feelings verbally. Art-based therapies rely less on cognitive ability and verbal skills and aim to promote mental health. Drama therapy provides a playful framework to communicate problematic issues and to foster social skills. Improvisational theatre (improv) methods applied in therapy settings were reported to show positive effects on social competences and self-esteem. This pilot study investigates the feasibility (N = 24) and appropriateness (n = 12) of an intervention using improv methods in people with mild to moderate ID. Feasibility was measured on the basis of the average participation period, while appropriateness was assessed through a standardised patient satisfaction questionnaire (CSQ-8) and a self-developed questionnaire. The frequency of the applied methods was compared in two subgroups with participants requiring different support. The average participation rate of 19 months indicated a good feasibility. High CSQ-8 scores (M = 27.6/max. 32) and positive feedback on the self-developed questionnaire indicated the overall appropriateness. The frequency analysis of the applied methods reflected the adaptive nature of the intervention. Further research on the efficacy of improv methods contributing to mental health in people with ID is recommended.