This study was undertaken to document the phenotype of Kabuki (Niikawa–Kuroki) syndrome in patients from Australia and New Zealand, with particular emphasis on growth patterns, behavior, and relationship between head circumference and intellectual level. Data on 27 children and adults with Kabuki (Niikawa–Kuroki) syndrome from Australia and New Zealand were collected by questionnaire and clinical assessment. The patients ranged in age from 7 months to 36 years with a mean age of 7 years and 2 months. The mean age at diagnosis was 3⅚ years, but in most cases, the facial phenotype was evident from infancy. The minimum birth prevalence was calculated at 1 in 86,000. Three of our patients died. Parents reported a behavior phenotype characterized by an excellent long‐term memory and avoidance of eye contact. No correlation was found between head circumference and severity of intellectual disability. Eight of 14 patients over the age of 5 years were overweight or obese. Six of these eight patients had failure to thrive in infancy. One patient developed insulin‐dependent diabetes mellitus in adolescence. Some individuals with Kabuki (Niikawa–Kuroki) syndrome show a characteristic growth profile with failure to thrive in infancy progressing to obesity or overweight in middle childhood or adolescence. A behavior phenotype was noted which requires further investigation. Head size is not a predictor of degree of intellectual disability. © 2004 Wiley‐Liss, Inc.