Growth of juvenile redclaw Cherax quadricarinatus fed 400 g kg−1 crude protein isoproteic diets substituting fish meal with soya bean meal at various levels (250, 500, 750 and 1000 g kg−1) was evaluated under laboratory conditions. Juvenile crayfish were reared individually in 1‐L plastic containers for 56 days. Total survival was recorded for all treatments at the end of the experiment. There were no significant differences (P > 0.05) for the specific growth rate among the treatments, although the animals fed with the control diet (100% fish meal) obtained the highest mean daily weight gain (0.055 g day−1), individual final weight (4.12 g), molts per individual (0.04 molts day−1) and molting frequency (23.57 days) values at the end of the experiment. Dietary inclusion of soya bean meal at the tested levels hampered the C. quadricarinatus juvenile growth.