Abstract: This study was conducted at Al-sha`ulla Research Station, Ministry of Agriculture on 32 ISA broilers to study the replacing of Narbon vetch for soybean at 0, 10, 20 and 30% in the feed. The following parameters were examined, body weight, relative organs weight, haemoglobin concentration, packed cell volume, cholesterol, alkaline phosphatase enzyme and glutamic oxaloacetic transaminase enzyme. Liver and kidney tissues were also examined for histological changes. The data shown that Narbon vetch decreased significantly (p<0.01) body weight and increased (p<0.01) relative kidney weight. Haemoglobin concentration, packed cell volume and alkaline phosphatase activity were also decreased significantly (p<0.01). Histological examination of the kidney revealed a cute tubular nephrosis.