Understanding the process of recognising autism spectrum disorders (ASD) in children is important, both for achieving timely identification of children's difficulties and for ensuring positive experiences for families. Professionals working in primary care services are suitably positioned to identify children requiring referral for diagnostic assessment of ASD through their early contact with children and their families. Speech and language therapists (SLTs) in particular are well situated to recognise ASD, as concerns regarding communication development are frequently raised by parents of children who later go on to receive an ASD diagnosis. This small-scale qualitative study aimed to explore primary care SLTs' experiences of recognising potential ASD in children. Five SLTs working in primary care services in the Republic of Ireland participated in semi-structured interviews. Thematic analysis of the data revealed that participants were concerned with two key events: firstly, accurately recognising potential ASD in children; and secondly, discussing the possibility of ASD with parents. The SLTs' experiences of these events were found to be influenced by both individual and wider organisational factors. The findings are discussed in the context of the current literature on ASD identification and implications for practice are considered.