Background: Complementary and Integrative Medicine (CIM) shows positive clinical benefit with minimal side effects, yet, challenges to effective integration of CIM providers in biomedical health care settings remain. This study aimed to better understand the role evidence played in the process of integration of complementary therapies into a large urban pediatric hospital from the perspective of patients, caregivers, providers, and administrators through applied medical ethnography. Methods: An ethnography was conducted over the course of 6 months in a large urban pediatric hospital in the Southern United States. At the time, the hospital was piloting an integrative medicine (IM) pain consult service. Purposive sampling was used to select providers, patients, administrators, and caregivers to follow as they engaged with both the preexisting pain service and pilot IM pain services. Field observation and interviews were conducted with 34 participants. Thematic content analysis was used to analyze field notes, interview transcripts, and documents collected. Findings: Analysis of the data revealed five themes regarding the role of evidence in the process of integration: Anecdotal Evidence and Personal Experience Effecting CIM Use, Open to Trying Whatever Works, Resistance to the Unfamiliar, Patients and Parents Trusting Doctors as Experts, and Importance of Scientific Evidence to Biomedicine. All themes address the role of evidence in relationship to acceptance of complementary therapies and correspond with three thought processes: critical thinking, relying on others for evidence, and reactionary thinking. Conclusion: Both scientific and anecdotal evidence informed CIM use in this context. Biomedical environments seeking to integrate CIM into pain treatment regimens will need to engage all relevant stakeholders in building education, clinical training, and research programs that are critically informed about the context and evidence for CIM.