According to the WHO, about 3 million people die each year due to ambient air pollution. Most of the in vivo studies on the PM2.5 effects have been done on respiratory and cardiovascular tissues. However, little is known about the effects on the tissues involved on xenobiotic removal, such as kidneys. In the present study we assess the harmful effects of sub-chronic exposure to PM2.5 on the kidney, by investigating histologic and serum alterations in healthy and hypertensive rat models. Mean PM2.5 concentrations during exposures were slightly above the daily WHO standard. Exposed animals showed fibrosis, mesangial expansion, decrease glomerular and tubular lumen volumes in kidneys, with an elevated BUN. Hypertensive animals also exhibited much more severe alterations than healthy animals. We conclude that PM2.5 induces minimal or small-scale abnormalities that can be determinant for renal health preservation.