Apoptosis is a highly conserved process that plays an important role in controlling tissue development, homeostasis and architecture. Dysregulation of apoptosis is a hallmark of numerous human pathologies including hypertension. In the present work we studied the effect of hypertension on apoptosis and the expression of several apoptotic signaling/regulatory proteins in four functionally and metabolically distinct muscles. Specifically, we examined these markers in soleus (SOL), red gastrocnemius (RG), white gastrocnemius (WG) and left ventricle (LV) of 20 wk old normotensive Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR). Compared to WKY rats SHR had a significantly greater heart weight, LV weight and mean arterial pressure. In general, SHR skeletal muscle had increased Bax protein, procaspase-3 protein, caspase 3 activity, cleaved poly (ADP-ribose) polymerase (PARP) protein and DNA fragmentation as well as decreased Bcl-2 protein and a lower Bcl-2:Bax ratio. Subcellular distribution studies demonstrated increased levels of AIF protein in cytosolic or nuclear extracts as well as elevated nuclear Bax protein in SHR skeletal muscle. Moreover, Hsp70 protein in RG and SOL was significantly correlated to several apoptotic factors. With the exception of lower Hsp90 protein levels in SHR no additional differences in any apoptotic markers were observed in LV between groups. Collectively, this report provides the first evidence that apoptotic signaling is altered in skeletal muscle of hypertensive animals; an effect which may be mediated by both caspase-dependent and -independent mechanisms. This pro-apoptotic state may provide some understanding for the morphological and functional abnormalities observed in skeletal muscle of hypertensive animals.