Adiponectin is an anti-inflammatory adipokine produced by adipose tissue and its concentration is depressed in obesity and systemic arterial hypertension. Studies have established a relationship between the adiponectin plasma concentration and complications such as obesity and renal diseases. Proteinuria indicates renal dysfunction or infection and has a negative correlation with adiponectin plasma concentrations. The Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR) exhibited higher urinary protein concentrations when compared to Wistar rats (WIS). Therefore, this study aimed to evaluated the serum concentrations of adiponectin and its relation to proteinuria in these rats. The results indicate that WKY present a reduction in the adiponectin serum concentration when compared to WIS and SHR. The low production of adiponectin is related to proteinuria and to the heavy weight of these animals. SHR exhibit similar serum adiponectin levels to WIS, suggesting the hypertension as the responsible factor for the renal dysfunction.