Pain is a complex biobehavioral phenomenon. The quantification of pain involves the incorporation of many factors, including physiologic, behavioral, and psychologic factors. Recognition of pain relies heavily on the expression of the patient as well as the interpretation of the caregiver. There are many studies published on biobehavioral pain assessment tools, such as neuroimaging, neuromuscular, biomarker, and behavioral pain assessment scales. These tools present a clinical challenge to appropriately assess and manage pain in the noncommunicative pediatric patients, such as infants, preverbal toddlers, and intubated and/or unconscious or cognitively impaired patients. Pain is a combination of physiologic, behavioral, and psychologic interactions. Any tool that incorporates the measurement of only one of those domains is inherently incomplete in the assessment of pain. Therefore, the purpose of this literature review was to provide a comprehensive overview of these biobehavioral pain assessment tools used in pain assessment in the noncommunicative pediatric population.