Results using 99mTc stannous phytate as a lymph node imaging agent in animals [rats, rabbits dogs] were described. After s.c. administration there is good visualization of the draining nodes, best obtained 2-4 h from the time of injection. There is also visualization of the liver, spleen, kidneys and bladder. This agent appears suitable for lymph node imaging in areas where the extranodal concentration does not interfere. [This method should be expecially useful for detection of malignant lymph node metastases.].