The purpose of this study was to examine the development and construction of vocal and verbal expression of postoperative pain in young children with limited linguistic abilities. The main objective was to highlight specific pain vocalizations, which may lead to easy and quick detection and assessment of postoperative pain relative to the age of the suffering child. Forty-seven children aged 1 to 6 years were observed during two periods of surgical hospitalization: a preoperative and a postoperative period. The results showed that there was a significant relation between their age and the types of vocalization they expressed during the postoperative period. Regarding the development in relation to certain contexts, a minor modification seems to be concerned not with the type but with the frequency of the items of vocalizations. The study confirms earlier observations and clinical experience that an efficient and reliable assessment of pain in infants and young children necessitates taking several factors into account, such as the developmental age of the children, and especially a consideration of the whole spectrum of pain markers present in the child's behavior and captured by the assessment tools.