Studies of miners provide the basis for public health efforts to reduce residential radon progeny exposure. Because the preponderance of households do not have members who smoke indoors, studies of nonsmoking miners contribute essential data for risk assessments for residential radon progeny exposure. We studied a cohort of 2216 never smokers who were underground uranium miners employed in the western U.S. from 1956 to the early 1990s and who participated in a screening program for lung cancer conducted by Saccomanno and colleagues. After determining the vital status and cause of death in the cohort, we conducted a nested case-control study of 55 lung cancer deaths and 3 age-matched controls for each case. We found a steep nonlinear exposure response relationship without an apparent threshold in this study of male miners. The relative risk of lung cancer was 29.2 (95% CI 5.1,167.2) for miners with greater than 1450 WLM compared with those exposed to less than 80 WLM. Temporal factors affected risk, including average dose rate, which was inversely associated with lung cancer risk, and the length of time since last exposure, which was directly associated with decreased risk. As in studies of nonsmokers and smokers combined, we observed a nonlinear exposure response relationship in never-smokers, which resulted, in part, from an inverse dose rate effect and exposure misclassification. Our finding may contribute to risk assessment for residential radon progeny exposure in nonsmoking households and inform cost benefit analyses for remediation.