Polyglycolic acid mesh has been introduced as a method of controlling hemorrhage in severely damaged spleens. This study examines the effect of splenic wrapping on the immune function of the spleen, and also on its ability to control splenic bleeding in trauma patients. Thirty purebred beagle dogs were divided into three groups and subjected to sham operation (Group 1), splenectomy (Group 2), and splenic wrap (Group 3). Immunologic studies showed no difference between the wrapped group (Group 3) and those with their spleens intact (Group 1) in the induction of specific antibody-producing lymphocytes in splenic tissue after the injection of attenuated Pneumococci. All splenic injuries treated at Cook County Hospital between January 1985 and May 1988 were retrospectively analyzed. Of 60 patients with splenic injuries, 14 underwent mesh splenorrhaphy without mortality or serious complications. This study demonstrates that the immune function of spleen is preserved following mesh splenorrhapy, and that this technique can be used in a clinical setting with safe and efficacious results.