SSeCKS (src suppressed C kinase substrate) functions in the control of cell signaling and cytoskeletal arrangement. It is expressed in brain and spinal cord, but little is known about its expression in peripheral nerves. In this study, in rats, real-time polymerase chain reaction and Western blot analysis showed that expression of SSeCKS in crushed sciatic nerve reached its highest level 6 hr after crushing, whereas in a transection model, SSeCKS peaked at 2 days in the proximal stump and 12 hr in the distal stump. Immunohistochemical analysis demonstrated up-regulation of SSeCKS protein surrounding the crush site and in the two stumps of the transected nerve. In addition, SSeCKS colocalized with growth-associated protein 43 and with S100, which also changed with time after injury. These findings support the idea that SSeCKS participates in the adaptive response to peripheral nerve injury and may be associated with regeneration.