Comparative anatomical study of papillary muscle complexes and septomarginal trabeculea of adult human and sheep hearts was done to assess the similarities and dissimilarities between them. The comparative studies of papillary muscles would influence the understanding of the functional anatomy of the sub-valvular apparatus which could be applied for reconstructive surgery. The internal structure of the heart differs from species to another species. Also even in the same species, no one heart was exactly the same as another.