OBJECTIVE: To examine patterns of, and decision-making processes, informing referrals for inpatient access to integrative medicine (IM) services at a large, acute care hospital. DESIGN: Retrospective electronic health record review and structured qualitative interviews. SETTING: A 630-bed tertiary care hospital with an IM service available to inpatients. PARTICIPANTS: IM referrals of all inpatients aged ≥18 years between July 2012 and December 2014 were identified using the hospitals electronic health record. Fifteen physicians, 15 nurses and 7 administrators were interviewed to better understand roles and perspectives in referring patients for IM services. RESULTS: In the study hospital, primary sources of referrals for IM services were the orthopaedic and neuroscience/spine service lines. While the largest absolute number of IM referrals was made for patients with lengths of stay of 3 days or fewer, a disproportionate number of total IM referrals was made for patients with long lengths of stay (≥10 days), compared with a smaller percentage of patients in the hospital with lengths of stay ≥10 days. Physicians and nurses were more likely to refer patients who displayed strong symptoms (eg, pain and anxiety) and/or did not respond to conventional therapies. IM referrals were predominantly nurse-initiated. A built-in delay in the time from referral initiation to service delivery discouraged referrals of some patients. CONCLUSIONS: Conventional providers refer patients for IM services when these services are available in a tertiary hospital. Referral patterns are influenced by patient characteristics, operational features and provider perspectives. Nurses play a key role in the referral process. Overcoming cultural and knowledge differences between conventional and IM providers is likely to be a continuing challenge to providing IM in inpatient settings.