To evaluate serum markers for the diagnosis of Candida pyelonephritis, levels of D-arabinitol, candidal mannan antigen and candidal protein antigen were measured using an enzymatic fluorometric assay, an enzyme immunoassay and a latex agglutination assay, respectively. The study group comprised 36 patients with candiduria (11 disseminated candidiasis, 9 Candida pyelonephritis and 16 colonization) and 27 without candiduria. The D-arabinitol/creatinine ratio was the only marker that differentiated between Candida pyelonephritis and colonization (p < 0.01). Using the cut-off values (1.4 mumol/mg of D-arabinitol/creatinine ratio, 0.28 of mannan/creatinine ratio (x 10(4)) and 1:4 of protein antigen titer) D-arabinitol/creatinine ratio showed the highest sensitivity in Candida pyelonephritis (77.8%) as compared to mannan/creatinine ratio (55.6%) and protein antigen titer (11.1%) although there were no differences in specificity, positive predictive value or negative predictive value. These results suggest that D-arabinitol/creatinine ratio is the most useful marker of Candida pyelonephritis.