Lung cancer is one of the leading causes of cancer deaths worldwide. The poor patients prognosis is largely attributable to the lack of effective early detection methods. Based on the concept that proteins and peptides can emanate from tumor to the serum, the present study aims to investigate if serum proteins pattern, assessed by a gradient polyacrylamide gel, is capable to discriminate 66 lung cancer patients from 44 healthy donors. Additionally, in a group of 10 patients and 10 healthy donors, it was also investigated by western-blot if apoptosis and metastasis-related proteins such as Bax, Bcl-2 and Hlm were present in serum. Our results showed that, in patients, protein bands of 180 kDa and 13 kDa were more frequent (Fisher, P<0.05) and a protein band of 124 kDa was more intense (Mann Whitney, P<0.05). In healthy donors a band of 158 kDa were more frequent (Fisher, P<0.05), a band of 24 kDa was more intense (Mann Whitney, P<0.05) and bands of 14 kDa and 9 kDa were together more frequent (Fisher, P<0.05) and intense (Mann Whitney, P<0.05). Bax, Bcl-2 and Hlm were not detected in serum. We conclude that changes in serum protein pattern of lung cancer patients can be detected by a simple methodology.