Smoking carries a risk of oral cancer. Smoking generates free radicals, which are responsible for the high levels of cellular lipid peroxidation along the oral mucosa. Free-radical-induced lipid peroxidation has been implicated in the pathogenesis of oral cancer. Malondialdehyde (MDA) is the end-product of lipid peroxidation and can serve as a marker of the degree of lipid peroxidation. This study aimed to determine the salivary MDA levels in smokers and to use salivary MDA levels to assess the risk of developing oral pre-cancer and cancer. We hypothesized that heavier smokers would exhibit greater levels of salivary lipid peroxidation which in turn would correlate with a greater risk of oral pre-cancer and cancer. To test our hypothesis, we devised QuitPuff, a simple, home-based test consisting of a diagnostic reagent that reacts with MDA and produces a color change in a sample of saliva. We measured the MDA level in each sample by matching the color change with a colorimetric Lipid Peroxidation Index (LPI) chart. This method was tested on 125 people and the results were validated by UV Spectroscopy. The test detected the degree of salivary lipid peroxidation with 96% accuracy. We found that heavier smokers exhibited greater levels of salivary MDA. QuitPuff, a simple and inexpensive home-based test, can serve as an early, safe, non-invasive test for smokers to measure their degree of salivary lipid peroxidation and thereby assess their risk of developing oral pre-cancer and cancer.