The objective of this pilot study was to evaluate the effectiveness of a group-based intervention aiming at improving social and communication skills in individuals with autism spectrum disorder. Over a period of 11 months, N = 17 children and adolescents received treatment according to the manualised Frankfurt Social Skills Training (KONTAKT). Parent, teacher, expert and blind expert ratings were assessed to judge outcome regarding peer interaction, autistic behaviours, adaptive functioning and family burden. The participants exhibited improvements pre to follow-up treatment, particularly in the area of autistic symptomatology. Effect sizes (partial eta squared) ranged from 0.02 to 0.69. Among other things, regression models showed a positive influence of IQ and language skills on gains in social skills. Findings indicate that KONTAKT might be useful for enhancing social skills and reducing autism-related psychopathology over time in different contexts. Nevertheless, controlled trials are needed to reassure its effectiveness