Composite renal end points and end stage renal disease (ESRD) are frequently included as prespecified secondary end points in the cardiovascular outcomes trials (CVOTs) of diabetes medications. We examined the heterogeneity in the definitions of composite renal end point and ESRD in CVOTs. Five criteria (macroalbuminuria, doubling of serum creatinine, estimated glomerular filtration rate [GFR], ESRD and renal death), were considered for the renal composite end point across the trials. Only three of the 12 trials included all five criteria, whereas the other trials included different combinations of four, three and two criteria. ESRD definition also showed considerable heterogeneity across the trials. Heterogeneity exists in the definitions of renal composite and ESRD end points in CVOTs making it challenging to assess comparative efficacy of the active treatments for reimbursement purposes.