The author characterizes in detail 4340 patients with diffuse renal lesions (chronic glomerulonephritis, renal amyloidosis, lupoid nephritis, diabetic glomerulosclerosis and nephrosclerosis) coupled with different diseases of the urinary organs including urolithiasis, cancerous and tuberculous processes, purulent diseases of the kidneys and prostatic lesions. Stage III chronic renal failure (CRF) was revealed in 2073 (57.1%) out of the 4340 patients. All of them died because of uremia. The mean lifespan of the patients was 1.6 +/- 0.1 yr. since manifestation of the concomitant process. The shortest times of CRF onset, the highest frequency of stage III CRF and the least lifespan were noted in patients with double association, particularly in those suffering from associated chronic glomerulonephritis with renal amyloidosis and urinary bladder cancer in the stage of compression with tumor of the intramural parts of the ureters, namely they were 0.6 +/- 0.1, 100% and 1.0 +/- 0.1 yr., respectively. The author holds that the main reason for such an abrupt CRF onset in patients with concomitant renal lesions of any type lies in simultaneous combined influence on the kidneys of absolutely different diseases bearing in mind their etiology and pathogenesis. Besides, according to the author's data, considerable influences on the times of CRF onset and rates of its progress are produced by both the course and stage (phase) of the development of each of the coexistent diseases. Attention is drawn to the necessity of early participation of urologists in the solution of the problems concerned with the policy of managing nephrological patients with diseases of other organs of the urinary system as well as with permanent dynamic follow-up of all the patients with concomitant processes, especially with double ones.