|Proteinuria is a condition characterized by excessive excretion of proteins in urine. This study evaluated differences in urinary protein profiles among healthy individuals, patients with proteinuria of unknown cause (PRU) and caused by Histoplasma antigenuria (HAG). Of the 118 human proteins identified, 24 were in common among the three groups. The number of unique human proteins in samples from healthy individuals, patients diagnosed with PRU and HAG, were 13, 19 and 25, respectively. Significant differences in the urinary protein profiles and their associated biological pathways reflect the complexity of systemic and renal changes of human response to underlying diseases.