Pharmacological therapy of surgical disease often involves manipulating the physiologic balance between pro- and anti-inflammatory responses. Many agents target only one aspect of the inflammatory cascade. Originally identified as a protein elaborated by T-lymphocytes, IL-10 appears to globally inhibit cytokine production. The purpose of this manuscript is to examine the immunomodulatory and anti-inflammatory effects of interleukin-10 (IL-10) in an attempt to define the clinical utility of IL-10, both as a marker of and as a therapeutic strategy for intervention in inflammatory and immune-mediated diseases, IL-10 is elaborated from multiple sources and has diverse cellular effects to regulate immune and inflammatory responses. Accumulating evidence suggests that the anti-inflammatory influence of IL-10 observed at the cellular level may be manipulated to impact the immune and inflammatory-mediated responses associated with injury and sepsis, gastrointestinal and cardiovascular disease, and transplantation. In conclusion, IL-10 is an important mediator of immune and anti-inflammatory responses in surgical disease and, as such, has therapeutic promise as an immunomodulator and as an anti-inflammatory agent.