Despite advances in research and technology, investigators around the world acknowledge the continued undertreatment and unnecessary suffering of children in pain. The dilemma of inadequate relief of children's pain may relate to the complexity of the pain phenomenon. Using the Gate Control Theory as the foundation for this work, the purpose of my study was to determine the extent to which selected variables (severity of operative procedure, postoperative use of pharmacological agents, prior experience with pain, pain tolerance, gender, and age) predicted children's and adolescents' pain following spine fusion. Using a descriptive correlational design, data were collected from 93 children (ages 8 to 21 years) who had undergone spine fusion. For four consecutive postoperative days, children were asked to rate the intensity of their pain using the Adolescent Pediatric Pain Tool and observed pain behaviors were recorded using the Child Pain Scale. Repeated measures MANOVA revealed that children continued to experience moderate to severe pain throughout the four days. Stepwise multiple regression analyses were conducted for each postoperative day on each of the dependent variables. A modest amount of variance in children's pain was explained by the variables studied. R square values suggested that age, pain tolerance, and severity of operative procedure have the greatest potential as predictors of children's postoperative pain and warrant future research.