A lubricant for use in hot rolling of high chromium stainless steel, the lubricant being continuously supplied to surfaces of hot rolling rolls in contact with the steel being rolled at least during hot rolling of the stainless steel, which lubricant comprises a viscous aqueous solution of water soluble high molecular weight thickener and from 10 to 40% by weight of iron hydroxide powder dispersed in the aqueous solution, said iron hydroxide powder having a median particle size of from not less than 0.1 mu m to less than 1 mu m and said lubricant having an apparent viscosity within the range of from 1,000 to 50,000 cP.