The effects of dietary replacements of fish meal with soybean meal on growth performance, heamatology and serum biochemistry in juvenile Labeo cubie were evaluated. Four hundred and fifty (450) apparently healthy juvenile Laboe cubie were distributed into one of fifteen 1000 L tanks divided into five groups and fed any of diets A (0% soybean meal); B (30% soybean meal); C (40% soybean meal); D (45% soybean meal) and diet E (75% soybean meal) for 56 days. At set time points day 7, 14, 28 and day 56, five fish were randomly selected per tank for growth assessments, heamatology and serum biochemical evaluations. Growth performance indices decreased significantly (p < 0.05) along the gradient of soybean meal inclusion and the duration of feeding. The erythrocytes count increased significantly (p < 0.05) at day 14 in fish fed soybean meal diets and decreased significantly (p < 0.05) beginning at day 28 in fish fed soybean meal-based diets. The haematocrit of fish fed diets D and E were significantly (p < 0.05) lower at day 28 compared to day 56. There were no significant variations in haemoglobin concentration and the leucocytes counts (p > 0.05). The proteins, blood glucose and the transaminases increased significantly (p < 0.05) along gradient of dietary inclusion and duration of feeding in the first 28 days while creatinine kinase activity, blood urea nitrogen and uric acid concentration remained significantly elevated (p < 0.05) in fish fed the soybean meal-based diets. The results of the study show juvenile L. cubie may tolerate up to 40% dietary inclusion of soybean meal as replacement for fish meal.