The natural history of chronic kidney disease (CKD), in general, remains conjectural. Current literature on rates of progression to end-stage renal disease (ESRD) as compared with mortality in CKD shows conflicts. A study of 27,998 patients in managed care reported a 5-year ESRD rate of 20% and a death rate of 50%. In 1666 patients in the Modification of Diet in Renal Disease study, a much higher ESRD rate of 60% after 88 months was reported (four times the death rate); among patients older than 65 years, the death rate approximated the ESRD rate. More than 20 million Americans have CKD [estimated glomerular filtration rate (eGFR) < 60 mL/min). Annually, approximately 100,000 new U.S. patients develop ESRD, accounting for a casual annual ESRD rate of only 0.5% among the U.S. CKD population. Similarly, this author's anecdotal experience suggests a more benign CKD outcome than is suggested by the two foregoing studies. A 72-month prospective report of an aging cohort of 100 CKD patients, high risk because they all experienced acute kidney injury at study entry, is presented. The finding of an approximately 18% ESRD rate and 13% death rate after 4 years contrasts sharply with the two studies cited earlier. Several factors--prospective as compared with retrospective analysis, varying patient age and other variables, managed care as compared with other care, and other unknown variables--play important roles in CKD outcome. This author agrees with researchers who recently emphasized the heterogeneity of the CKD population. Patient prognosis and management must be individualized.