This study used Interpretative Phenomenological Analysis (IPA) to investigate the experiences of African immigrant mothers living in the UK with a child diagnosed with an Autism Spectrum Disorder (ASD). Six mothers took part in one-off semi-structured interviews. The results indicated five themes: caring for a child we didn’t expect, the pain of stigma and rejection, making sense of our child’s difficulties and diagnosis, negotiating conflicting belief systems and faith as “key”. Many aspects of the mothers’ experiences appear related to their position as immigrants from cultures with very different belief systems regarding child development and disability. Stigma, blame and social isolation appeared to compound the difficulties they experienced. Conflicts between African cultural beliefs and a western, medical understanding of ASD, appeared to create a feeling of cognitive dissonance for the mothers. The strategies they used to negotiate this appear to map onto Berry’s (2005) acculturation strategies, suggesting the experience of having a child with ASD impacts upon the acculturation process. Implications for clinical practice and policy are discussed, including the importance of raising awareness of ASD among immigrant communities, supporting parents to integrate conflicting belief systems and facilitating the development of peer-support groups within minority communities