Abstract Despite antibiotic therapy intra-abdominal sepsis following major surgery is a significant cause of mortality. We sought to determine if interleukin-1β (IL-1) could improve survival in a murine model of intra-abdominal infection. Groups of 10 BDF 1 mice received a single subcutaneous (sc) injection of recombinant human IL-1β 24 hr prior to cecal ligation and puncture (CLP) and were assessed twice daily for survival. Mice that received a single injection of IL-1β 24 hr prior to CLP had a dose-dependent improval in survival compared to controls. The beneficial effect of IL-1 treatment may have been related to its ability to stimulate myelopiesis. The addition of indomethacin, in an effort to limit possible toxicity of IL-1, did not further improve survival. Appropriate timing of specific immunomodulators may provide an additional strategy for the treatment of infections.