The proteins fibrin, fibrinogen, fibronectin and complement C5b-9 were investigated in mechanically damaged skeletal muscle. An accumulation of fibrin, fibrinogen and fibronectin could be observed immediately after intra-vital trauma in damaged fibre zones, later an accumulation at the torn edges of the fibres. The accumulation of complement C5b-9 began one hour after trauma. After post mortem trauma no positive reactions could be observed for any of the proteins. The degree of expression of these proteins can therefore be used to differentiate between vital and postmortem muscle damage as well as the estimation of wound age in the early antemortem time period.