We quantified the burden of vesicoureteral reflux and ureteroceles in the United States by identifying trends in the use of health care resources and estimating the economic impact of the diseases.The analytical methods used to generate these results were described previously.Annual inpatient hospitalizations for vesicoureteral reflux increased slightly between 1994 and 2000 from 6.4/100,000 to 7.0/100,000 children, although this trend did not attain statistical significance. Inpatient hospitalization for ureteroceles remained relatively stable between 1994 and 2000 at an average of approximately 2,818 cases annually (1.0/100,000 to 1.1/100,000 children). The rates of visits to physician offices doubled during the 1990 s for commercially insured children (12/100,000 in 1994 and 26/100,000 in 2002) and children covered by Medicaid (43/100,000 in 1996 and 85/100,000 in 2000). Overall the rate of ambulatory surgery visits by commercially insured children increased from 3.4/100,000 in 1998 to 4.8/100,000 in 2002. Similar estimates were not available for children covered by Medicaid. Emergency room use by children with a primary diagnosis of vesicoureteral reflux was rare, reflecting the trend toward delivery of care at physician offices, ambulatory surgery centers and inpatient hospitals. No reliable data could be obtained on outpatient visits or ambulatory surgery for ureteroceles. In 2000 total expenditures for inpatient pediatric vesicoureteral reflux were $47 million, an increase of more than $10 million since 1997. Based on data from 2000 the yearly national inpatient expenditures from ureterocele treatment were an estimated $4 million.The economic impact of inpatient treatment for pediatric vesicoureteral reflux is considerable. If other service types such as pharmaceuticals, and outpatient and ambulatory services were considered, the observed impact of this condition would certainly be greater. Importantly the costs of prophylactic medical therapy and emerging therapies such as Deflux are not accounted for in this estimate. Furthermore, indirect economic costs, such as work loss to parents of children with pediatric vesicoureteral reflux, were not considered, causing an even greater underestimation of the true costs associated with the condition. Although the National Association of Children's Hospitals and Related Institutions, and the Health Care Cost and Utilization Project Kids' Inpatient Database include data on ureteroceles, the data were limited and, thus, they could not be used to determine reliable cost trends. Available data indicate that the mean cost per ureterocele case was almost $8,000 with little variation observed across ages, regions or sexes.