A method for enhancing strength and hardness of powder metallurgy stainless steels comprises steps of fabricating a stainless steel powder into a green compact; placing the green compact in a reducing environment and maintaining the green compact at a sintering temperature to form a sintered body; and placing the sintered body in a carbon-bearing atmosphere and maintaining the sintered body at a carburizing temperature below 600° C. to implant carbon atoms into the sintered body and form carburized regions in the sintered body. Thereby, the strength and hardness of powder metallurgy stainless steels can be improved. As the carburizing temperature is lower than 600° C., chromium would not react with carbon. Therefore, the strength and hardness of powder metallurgy stainless steels can be enhanced and the superior corrosion resistance is still preserved.