Objective To explore parents' and professionals' perceived causes and treatment of Autism Spectrum Disorders (ASD) on the Kenyan Coast. Methods In-depth interviews and focus group discussions using guiding questions were utilized in data collection. One hundred and three participants, who included parents of children with ASD, special needs teachers, clinicians, and social workers from diverse cultural background, participated in this study. The interviews and focus groups were recorded, transcribed verbatim and then translated to English. Themes were generated using content analysis. Results Preternatural causes were mentioned and included evil spirits, witchcraft, and curses. Biomedical causes comprised infections, drug abuse, birth complications, malnutrition, and genetic related problems. Treatment varied from traditional and spiritual healing to modern treatment in health facilities, and included consultations with traditional healers, offering prayers to God, and visits to hospitals. Conclusions The results suggest that regardless of cultural backgrounds, people on the Kenyan Coast have similar views on perceived causes and treatment of ASD. These findings provide valuable conceptual understanding for professionals when planning and implementing community based rehabilitation interventions targeting children with ASD within a local context.