CO2 laser-photoacoustic technology was used to investigate the suitability of ethylene as biomarker for active smoking with electronic cigarettes (E-cigarettes) vs. traditional cigarettes (T-cigarettes). Higher levels of ethylene in the composition of breath after T-cigarettes inhalation was found in comparison with the inhalation with E-cigarettes. The goal of this study was to explore and verify that E-cigarettes are not a potential cause of damage in the human lung tissue at smokers. The CO2 laserphotoacoustic spectroscopy is suitable for the detection of ethylene in exhaled breath, producing feasible and reproducible results which discriminate active smoking with E-cigarettes vs. T-cigarettes. This study is probably the first measurement of the ethylene response from the damage of the human lung tissue at exhaled breath of E-cigarettes smokers. Exhaled breath air analysis using CO2 laser-photoacoustic spectroscopy is a non-invasive method, safe, rapid and acceptable to subjects, with promising potential in monitoring and diagnostics of ethylene patterns from active smoking vs. healthy breath samples.