1548 Background: Lung cancer screening continues to be an area of great opportunity in public health, especially in developing countries. In Mexico, about 10,000 new cases of lung cancer are detected annually, of which less than 5% are diagnosed in early stages. There are no national programs for timely detection of lung cancer in our country, so it is essential to seek accessible measures to prioritize resources for high-risk people. Methods: We developed a web app that consisted of a short survey to stratify patients according to their risk of lung cancer (https://cuccuanl.com/tamiz_pulmon/). The questions were based on Nelson's criteria to categorize high-risk subjects who are deemed candidates for screening. The program contained automated logic programmed using JavaScript to guide people to the low or high-risk page if they met standard risk criteria in those age 50 and older. The high-risk page alerted people of their risk, displaying general information about lung cancer as well as contact information to make an appointment at our cancer center. An appointment could be also scheduled within the app if the person so wished. The web app was launched and distributed through social media. Results: After a period of 2 months, 939 people completed the survey. The median age of the responders was 40 years, and 61% were men. Of the total, 185 participants were 50 years of age or older. 268 people (29% of the total) were sent to the high-risk page, including persons under 50 years of age with symptoms highly suggestive of lung cancer. According to their smoking status, 80% of the subjects reported active smoking, while 9% reported heavy smoking, considered as more than 20 pack-years. Among all the people evaluated, 44 high-risk subjects scheduled a specialized medical appointment within the web app. Conclusions: This pilot study showed a high response of Mexican population seeking lung cancer risk evaluation, especially among the persons who smoke regularly. The use of web apps can result in mass diffusion which will help reach people with less medical access, a common scenario in many developing countries. Further analysis should be made to measure the real impact on lung cancer diagnosis and oncological outcomes. Our study shows how effective social media is as a means of diffusion on health topics. [Table: see text][Table: see text]