This trial was conducted to study the ability of dietary propylene glycol to mitigate winter stress of Nile tilapia under biofloc system. Nile tilapia (average initial weight = 28.50 ± 0.25 g) were fed three isonitrogenous (257.75 g kg−1 crude protein) diets for 47 days in winter season. The first diet was free added with propylene glycol (PG) control. The other two diets were supplemented with 5 mL and 7.5 mL PG kg−1 diet, respectively. At the end of feeding trial, the highest survival rate (P < 0.05) was observed in tilapia fed the diet supplemented with 7.5 ml PG kg−1 diet. A linear response in weight gain (WG; P = 0.034), specific growth rate (SGR; P = 0.041) and protein efficiency ratio (PER; P = 0.038) of tilapia were found by the increase in the PG levels in diets. The supplemental diets with PG did not induce any significant differences (P > 0.05) on feed conversion ratio (FCR) and feed intake (FI) of fish. The activities of …