BACKGROUND: Fetal alcohol spectrum disorder (FASD) is a developmental disability. A diagnosis of FASD is vital for support and wellbeing. However, receiving a diagnosis can be challenging. The aim of this research was to understand the experiences and impact of diagnosis for caregivers of those with FASD in New Zealand. METHOD: We conducted focus groups with caregivers and whānau (family) to explore their experiences with FASD. The transcripts were analysed using reflexive thematic analysis. RESULTS: We identified three themes across the life course of diagnosis, barriers to diagnosis, meaning of diagnosis and life with diagnosis. CONCLUSION: A diagnosis is vital for caregivers of those with FASD. However, it is difficult to access a diagnosis in New Zealand due to professionals' lack of training, knowledge, and inadequate professional support. It is essential to build our professionals workforce competence and skills of FASD.