The present study aimed to estimate postmortem interval through immunohistochemical markers and 
histological examination of the skeletal muscle of rats at different time intervals. Fifty adult male 
albino rats were divided into five groups with 10 rats in each group. The rats were killed by cervical 
dislocation and the skeletal muscle samples were taken at times (zero, 24, 48, 72, and 96 hrs PM). The 
samples were subjected to histological and immunohistochemical examination. The results revealed 
that histological changes occurred gradually over the time since death. Immunohistochemical results 
of p53 and caspase-3 showed a significantly strong negative correlation with PMI. It was concluded 
that postmortem histological changes and immunohistochemistry of apoptotic markers (p53 and 
caspase-3) in skeletal muscle could be useful for estimating a postmortem interval.