Background and context: Thiruvananthapuram has the highest breast cancer incidence in India and majority of cases are detected late pointing to the inefficiency of early detection programs. Primary health care providers do not advise regarding regular screening and most women never resort to any screening practices. Mammogram is not cost-effective and clinical breast examination (CBE) is not popular as a screening modality in our population. Aim: To describe the conduct, utilization and outcome of mass screening program conducted in Thiruvananthapuram. Strategy: A mass screening program with media publicity to motivate organizations and residential associations was planned. CBE was conducted by one of the five lady doctors who were trained by an expert breast surgeon at a tertiary care center to detect suspicious lumps. All suspicious cases referred to experts who would further evaluate the cases at a clinic outside the tertiary care center. Advocacy and expert service at accessible sites and availability of expert service outside the tertiary care center at convenient timings improved the acceptance of screening. Intersectoral coordination, community participation, accessible expert services and appropriate technology were followed. Program/Policy process: 9942 women had CBE along with breast awareness in 101 camps over 66 days and it was probably “the first ever marathon breast cancer screening campaign” in the world. Sociodemographic variables, details regarding previous screening, breast symptoms and known risk factors were collected. Anyone with suspicious findings was referred to experts. Outcomes: 868 (8.73%) women with suspicious findings were referred to experts who advised 258 mammograms and confirmed breast cancer in 16 women (1.61 per 1000 women). Mean age was 45.46 years. 82.5% had screening for the first time. Uniformity in examination, three levels of screening and minimum utilization of diagnostic procedures makes this campaign distinct from others. All participants are kept on follow-up through a free clinic maintained by a nonprofit NGO in Thiruvananthapuram. Effective planning and selfless service along with coordinated effort of an apex institution (Regional Cancer Centre, Thiruvananthapuram), a private medical college (Sree Gokulam Medical College, Thiruvananthapuram) and media partners were the key to success. What was learned: Early detection of breast cancer is possible by CBE, provided women can be motivated for regular screening and adequate expertise is available. CBE campaigns can improve screening behavior and breast awareness among women. Primary health care providers and mass media could educate women regarding the benefits of breast awareness and motivate them for regular screening. Proper referral system including certified intermediate referral centers should be in place to ensure the success of early detection by CBE.