Adult C57BL/6 mice with surgically induced renal failure of 1-15 weeks' duration were examined for the presence of changes caused by the renal failure. Surgery consisted of the electrocoagulation of the entire surface of the right kidney followed 3 weeks later by contralateral nephrectomy. Control groups comprised normal mice as well as sham-operated mice subjected to the right kidney electrocoagulation followed by visualization of the left kidney rather than removal. Results indicate: (1) the surgical procedures to induce renal failure were free of local and systemic infectious complications, (2) moderate to severe degree of renal failure was consistently achieved and remained stable over the study period, (3) significant growth retardation of the renal failure mice was present throughout the study whereas sham-operated mice showed catch-up growth with normal controls by the 3rd week postsurgery, (4) anemia was a very early manifestation of the disease appearing by the 1st week after the induction of renal failure to reach its nadir by the 2nd week; a mild anemia was observed transiently postsurgery in sham-operated mice and ascribed to the renal injury, and (5) renal failure mice were free of visible changes of advanced uremia such as impaired wound healing, bleeding tendency and gross neurological deficits. This new experimental model is proposed as a tool for the study of the pathogenesis and treatment of chronic uremia. While developed to study the immunological disturbances of renal failure, this model could conceivably serve for the study of other abnormalities, anemia in particular.