Diabetes Mellitus (DM) is a metabolic syndrome characterized by hyperglycemia. Chronic complications affect a number of organs, including the lungs. Cissampelos sympodialis Eichl (Menispermaceae) is a plant used to treat respiratory diseases. The aim of this study was to evaluate the effect of Cissampelos sympodialis extract (CSE) in lungs of diabetic rats. We used 30 Wistar rats divided into three groups: control group (CG), diabetic group (DG) and diabetic Cissampelos sympodialis treatment group (DTG). Diabetes was induced by streptozotocin (40 mg/kg i.v.). The CSE (400 mg/kg, po) was administered daily, during four weeks, beginning one week after the onset of DM. The treatment with CSE was not able to reduce blood glucose levels after streptozotocin injection. However, it was able to decrease cholesterol and triglycerides and prevent damage on pancreatic islets morphology. Additionally, morphological alterations such as alveolar septa loss, inflammatory infiltrate and fibrosis were seen in lung tissue of rats with DM, and treatment with CSE apparently reversed these histopathological findings. Thus, CSE treatment reduced the lipid profile and restored the lung architecture of diabetic animals by a mechanism independent of glycemia and which might be associated with the reduction of the damage on the pancreatic islets.