Speech-language pathologists (SLPs) working in early childhood intervention are expected to have knowledge and skills across a number of areas and to engage in evidence-based practice. We explored the knowledge and perceptions of SLPs working with young children within Australian early childhood settings about augmentative and alternative communication (AAC), evidence-based practice, and barriers to such practice. Fourteen clinicians participated in group or individual interviews. Thematic analysis of the transcripts of these discussions revealed that they had a broad view of AAC and its benefits. Their reported assessment and intervention approaches reflected best practice as documented in the literature. The exception was in the implementation of family-centred practice. Although the participants involved families in their children's intervention, many appeared to use a directive approach. There was also evidence of struggling with families' negative attitudes about the use of AAC. A major barrier for these clinicians in implementing AAC and best practice was limited time in light of the many demands and expectations. Despite some frustration, these participants were passionate about their work and belief in the benefits of AAC for young children with varied communication difficulties. The results suggest that many expectations placed on clinicians within early childhood intervention settings may fail to take into account the everyday demands on their time, in a context of varied resources and support.