Background: Heat shock protein is one of the most abundant and best characterized heat shock protein family that consists of highly conserved stress proteins. Amongst these heat shock protein family, HSP70 is expressed in response to stress and plays crucial roles in environmental stress tolerance and adaptation. Thermal stress alters the normal body homeostasis and causes severe detrimental effects on production and productivity of animals and impairs growth, immune status of animal. Therefore, the present study is proposed to study HSP70 gene expression pattern in peripheral blood mononuclear cells. Methods: The present study was conducted to study the relative mRNA expression pattern of HSP70 gene in peripheral blood mononuclear cells (PBMCs) during different seasons in Padharpuri buffaloes. 10 Apparently healthy, non - pregnant Pandharpuri buffaloes (above 2 years of age) were taken for study. Blood samples were collected thrice i.e. once in winter season, once in summer season and once in rainy season. Real-time polymerase chain reaction was applied to investigate mRNA expression of HSP70 gene during different seasons. Specificity of the desired products was documented using analysis of the melting temperature and high resolution gel electrophoresis to verify that the transcripts are of the exact molecular size predicted. Result: To investigate the variation in relative mRNA expression profile of HSP70 gene, Glyceraldehyde 3-phosphate dehydrogenase (GAPDH gene) was used as a housekeeping gene. The relative expression values of HSP70 during summer and rainy seasons were found statistically significant in comparison to winter. These results suggest that HSP70 gene expression varies with season and this variation may play an imperative role in conferring thermo tolerance against heat stress during different seasons.