The present work was conducted to evaluate the influence of replacing fish meal with agricultural wastes on the haematological, serum biochemical, and immunological parameters. A total of 400 grass carp (Ctenopharyngodon idella), with an average body weight of 100.1±1 g, were used in the present study. The fish were randomly divided into 4 groups (100 fish/pond). A basal control diet was formulated to fulfill the nutrient requirements of the fish that contained 25% crude protein (CP). The other 3 diets (treatment diets) were the alfalfa diet, peanut leaves diet, and a mixture of alfalfa and peanut leaves diet. The fish were fed six days per week for 90 days at a daily feeding of 3% of the estimated fish weight of the total biomass of the fish, with twice-daily feeding at 8.00 am and 4.00 pm. Haematological analysis revealed that red blood cell (RBC) counts, haemoglobin levels (Hb), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC)   white blood cell (WBCs) counts, monocytes, and eosinophils were insignificantly different in the treated groups compared to the control group. While, Hematocrit (Hct), mean corpuscular volume (MCV) neutrophils, and platelets counts were significantly different from fish fed the plants feed diets compared to fish fed the control diet. Serum glucose, cholesterol, triacylglycerol, urea, and creatinine levels, as well as aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities were significantly increased in alfalfa + peanut leaves meal compared to the different feeding diets. Immunological parameters (IgM levels and lysozyme activity) were significantly improved by plants feed compared to the control group. These results revealed that the alfalfa induced the least side effects on the haematological and biochemical parameters in grass crap, while the mixture (alfalfa+peanut) highly improved the immune status, but induced the highest side effects on the haematological and biochemical parameters in grass crap.