The aim of the research was to establish whether valued outcomes could be identified with a particular autistic spectrum disorder (ASD)-specifc post-graduate certificate programme. The research investigated and compared the practice of six teachers who had participated in an ASD-specific continuing professional development (CPD) programme and four teachers who had not. A combined qualitative and quantitative case-study design was used in reviewing the literature, videoing classroom practice, conducting semi-structured interviews with class teachers, principals and other school staff. The data were interrogated through combining a specifically-constructed model for evaluating the aims, functions, impact and discrete elements of CPD with the concept o f grounded theory. The acquisition of a broad theoretical knowledge of ASDs, increased teacher-confidence, awareness of the autobiographical experiences o f individuals with ASDs and the development of lifelong learning, writing and research skills were identified as valued outcomes o f participating in the programme. An impact on promoting the principal’s management and instructional roles and employing a collaborative, inclusive whole-school approach was evident in schools where teachers had completed the programme. Bricolage and self-reflective practice also emerged as key contributing factors to teachers’ knowledge. The value o f access to a range of CPD models for teachers is affirmed provided that the quality o f programmes is assured. The research findings suggest that while initial teacher education (ITE) would benefit from further special education input, the contribution o f ITE to teachers’ repertoire of pedagogical knowledge in meeting the needs o f pupils with ASDs should not be underestimated. Significantly the research findings suggest the possibility of incorporating the strategies used in behavioural approaches in naturalistic classroom settings. The findings indicate that it is critical that teachers are in a position to adopt an individualised responsive ASD-pedagogy that incorporates both an understanding of the common pedagogic needs o f all learners and the group-pedagogic needs of learners with ASDs. The research findings further corroborate the fact that the literature to date, has failed to yield definitive conclusions in favour o f a specific intervention model for pupils with ASDs. It is suggested that an alternative approach based on isolating the effective elements o f common and ASD-specific teaching approaches may be more advantageous than pursuing the quest for a specific intervention model.