This study aimed to investigate the effects of dietary phytosterols on growth performance, digestion, antioxidant and immune responses, and hepatopancreas and intestinal morphology in Procambarus clarkii. Five diets were prepared by adding 0%, 0.10%, 0.19%, 0.38%, and 0.76% phytosterols to the basal diet, which were named CON, P1, P2, P3, and P4, respectively. The crayfish were cultured for six weeks, and their average body weight was (9.37±0.02) g. The results showed that the weight gain rate and specific growth rate in P1 and P2 were significantly higher than those in CON (P＜0.05), and the growth performance in P2 was the best. The protease activity in the gut in P3 was significantly higher than that in CON, while the lipase activity was significantly lower (P＜0.05). The acid phosphatase and alkaline phosphatase activities in P1 were the highest in the hepatopancreas, and the acid phosphatase and alkaline phosphatase activities in P2 were the highest in the hemolymph; however, there were no significant differences compared to those in CON (P＞0.05). As the phytosterol level increased, the total superoxide dismutase and catalase activity in the hepatopancreas and hemolymph increased, and the malondialdehyde content decreased. Compared with CON, the intestinal structure in P1 was improved. However, when the phytosterol level exceeded 0.10%, hepatopancreas and intestinal damage increased with the increase in the dietary phytosterol level. The expression of NF-κB in the hepatopancreas increased as the phytosterol level increased. The expression of Hsp70 in P1 was significantly higher than that in other groups (P＜0.05). In conclusion, 0.10%–0.19% dietary phytosterol could promote the growth and digestion of P. clarkii, improve the morphology of the intestinal and liver tissues, and enhance the antioxidant and immune responses of P. clarkii.