Pulsed acoustic cellular expression (PACE) is a treatment that applies focused acoustic shock waves to promote tissue healing. The aim of this study was to assess the effect of PACE treatment on inflammatory responses in a cremaster muscle ischemia/reperfusion injury model. Seventeen cremaster muscle flaps were evaluated in four groups: nonischemic controls (n = 5), 5-hour ischemia controls (n = 4), preischemic (5-hour) PACE conditioning (n = 4), and postischemic (5-hour) PACE conditioning (n = 4). The expression of proinflammatory cytokines (TNFα, IL-6, IL-1α, IL-1β, GM-CSF) and chemokines (CCL3, CCL4, CXCL4) was assessed using TaqMan® real-time PCR. Expression of ELAM-1, VCAM-1, and ICAM-1 was assessed by immunostaining. Preischemic PACE conditioning upregulated expression of IL-6, CCL3, CCL4, and CXCL4, and downregulated expression of TNFα, GM-CSF, and IL-1α. Postischemic PACE conditioning significantly decreased expression of all evaluated genes. Pre- and postischemic PACE conditioning decreased expression of ELAM-1 and ICAM-1. Results of the study indicate that application of PACE conditioning may have a beneficial effect on the recovery of tissues subjected to the ischemia/reperfusion injury. Postischemic PACE conditioning revealed anti-inflammatory effect as confirmed by decreased expression of inflammatory cytokines, chemokines, and cell adhesion molecules (ELAM-1 and ICAM-1) that are responsible for leukocyte recruitment into ischemic tissues. Hence, PACE therapy may be used effectively in clinical practice as a convenient therapeutic strategy to protect tissues against ischemia/reperfusion related injury after microsurgical procedures of free tissue transfers. © 2012 Wiley Periodicals, Inc. Microsurgery, 2013.