The present study was aimed with an objective to investigate the effect of heat challenge on the expression dynamics of heat shock protein 90 (HSP90) mRNA in cultured cardiac cells of goat. The heart tissues (n = 6) from different goats were used for the culture study. The cardiac cells obtained from different heart tissues were cultured in 24-well cell culture plates and incubated in a humidified CO 2 (5%) incubator at 39°C. The cardiac cells were allowed to become 75-80% confluent after 72 h of incubation. Then, the cardiac cells were subjected to heat challenge at 42°C for 0, 20, 60 and 100 min. The cardiac cells exposed to heat challenge at 42°C for 0 min was taken as control. The relative abundance of HSP90 mRNA was assessed by quantitative real-time PCR (qRT-PCR). The relative abundance of HSP90 mRNA did not change at 20 min of heat challenge as compared to control. Thereafter, the relative abundance of HSP90 mRNA was significantly increased (P < 0.05) at 60 and 100 min of heat challenge. However, the relative abundance of HSP90 mRNA was registered to be highest (P < 0.05) at 100 min of heat challenge. The present study suggests that overexpression of HSP90 mRNA could safeguard cardiac cell against the detrimental effect of heat stress and may provide thermo-tolerance to goat during extreme environmental conditions.