Heat shock protein 70 is highly conserved cytosolic protein which have important role in growth, development, and apoptosis. Hsp70 is well-known activator of macrophages and enhances the release of specific and non-specific effector molecules that have major role in tumor destruction and immunopotentiation of host. However, morphological effects of hsp 70 has not been carried out, therefore, morphological effects of hsp 70 on murine peritoneal macrophages were examined by light microscopy and scanning electron microscopy. Thioglycolate-induced peritoneal macrophages were prepared from BALB/c mice and cultured for 24 h in the presence of the hsp70. Tumor-associated macrophages treated with 10 μg/ml were varied in shape, mostly spindle shaped, i.e., stretched bidirectionally; surface ruffles were increased and their lamellipodia was prominent which suggest that hsp 70 treatment not only enhances the functional state of the peritoneal macrophages but also initiate immense morphological changes leading to increased endothelium adherence, increased antigen uptake, and increased migration to the inflammatory site.