Wolf-Hirschhorn syndrome (WHS) is a rare genetic condition with characteristic facial traits, organ malformations, functional impairment and developmental delay due to partial short arm monosomy of chromosome 4. Although several hundreds of cases have been published to date, a systematic collection of its clinical symptoms and anthropological traits is missing in the literature, and reports on abilities and needs of children with WHS are scanty. Results of detailed physical and developmental phenotype analyses in a 1 10/12-year-old boy with monosomy 4p15.2-pter are presented. Physical analyses were based on systematic data acquisition. They disclosed a total of 32 clinical symptoms and 46 anthropological traits. Developmental analyses were based on the child's interactive play in an environment structured according to Montessori principles. They disclosed a total of 44 abilities and a number of needs to be satisfied by the environment for the support of the child's psychic and intellectual growth. While the physical phenotype is important for the diagnostic process, the developmental phenotype is essential for parental counseling.