The polyamines are essential for rapidly growing cells. Polyamines is synthesized by two reactions which begin from arginine. The aim of this study is to examine the serum levels of the enzymes located in the putrescine synthesis pathway and their relationship with lung cancer. In addition, the study also aim determine the oxidant-antioxidant status and the oxidative stress index. This study was performed on 36 lung cancer patients and 36 healthy controls. The arginase activity and the ornithine level were determined spectrophotometrically while the arginine decarboxylase, ornithine decarboxylase and agmatinase levels were determined by using Enzyme Linked Immunosorbent Assay (Elisa kit). The total antioxidant (TAS) and total oxidant status...