Single session therapy (SST) has emerging evidence for facilitating meaningful therapeutic change in a small number of consults, rather than more traditional long-term therapies. This study aimed to explore and describe the parent/caregiver and child experience with advanced allied health practitioners (AAHP) using SST for children with developmental disabilities, by understanding key characteristics of the consultation that led to therapeutic change. Eligible families attending an AAHP outpatient clinic for children with developmental and behavioural concerns participated in one to four SST consultations around their identified areas of need. Semi-structured interviews were conducted with 38 parents and 12 children, from 37 different families. Thematic analysis was used to analyse interviews. Demographic information was gathered through parent interviews and by reviewing hospital records. Four key themes emerged relating to the characteristics of the consultation that led to a positive experience for families: (1) the art of mutual presence; (2) the value of time; (3) the power of understanding; and (4) the trust of action. These attributes were influenced by the overarching complexities of the AAHP, the parent's and child's interpersonal skills, and the organisational mechanisms influencing patient care. Parents and children reported clinical change during the consult through increased understanding, and being heard, valued, and respected for their individual decisions on how to manage their child's and family's needs. This study provides preliminary evidence that utilising SST for children and families with developmental and behavioural needs facilitates a positive experience valued by families. SST, with a focus on a family's individual identified areas of concern, was valued and effective when delivered by AAHP. This suggests that SST, when appropriately administered by experienced and trained health practitioners, is useful for families dealing with children with developmental and behavioural challenges.