Autism spectrum disorders (ASD) are often associated with intellectual disability (ID). ASD-specific group concepts usually focus on people on a high functioning level. The Autism-Competence-Group (AutCom) combines a psycho-educative approach with music and dance/movement interventions in adults with ASD and ID. AutCom includes 16 structured 90-minute sessions to foster social and emotional competencies. This study investigates the acceptability and effectiveness of AutCom. Practicability and acceptability were measured based on participation frequency and patient satisfaction (CSQ-8). Efficacy was assessed in a pre-post design (N = 12) based on self- and third-party assessment with a control group matched by gender and level of ID. Primary outcome variables were social and emotional competence, and secondary outcomes were challenging behavior and quality of life. A participation rate of 86% indicated practicability; high CSQ-8 scores (M = 30 of max. 32) indicated acceptability. Significant improvement was found in social competence compared to the control group and emotional competence in the pre-post self-assessment on the AutCom questionnaire. No significant improvement was found in challenging behavior and quality of life. AutCom is shown to be a promising and highly accepted group concept in fostering social and emotional skills in adults with ASD and ID.