Introduction: There is a substantial discrepancy between international and local prevalence rates for speech, language and communication needs (SLCN) amongst children in New Zealand. Reports of communication impairment are likely to be underestimates. Prevalence data can describe population characteristics and inform the scope and nature of services to adequately meet demand. Parents and other caregivers are central to the early identification of children with communication needs but they may not recognise their child's needs or act on their concerns. Method: Cross-sectional data were available for the Growing Up in New Zealand (GUiNZ) longitudinal study cohort at 24, 54 and 72 months of age, with 76% of whanau (families; n = 5241) completing three data waves. Descriptive and chi-square analyses were used to address: (1) What are the communication abilities of children in the first 5 years of life? (2) What do New Zealand parents understand of their children's communication? (3) Do New Zealand parents have concerns? (4) What are the trajectories of parental concern for children's communication in the first 6 years of life? Results: At 24 months old, 16% of children had communication skills that were of concern to their parents. At 54 months, there were concerns for 12.6% of children. Although most parents were able to describe their child's expressive abilities, many parents remained unconcerned when their child demonstrated communication skills that did not met developmental expectations. Conclusion: Parents can offer valuable insights about their children, but in many cases their level of concern about SLCN did not align with a professional view which reflects a more nuanced understanding of children's speech and language and the impact on future communication skills and needs. Increased awareness through public health messaging specifically regarding lifelong influences of communication challenges will aid in prevention, early detection and intervention.