This study sought to identify the causes of differences in the intensity of key talent management across firms by examining the environments and competitive strategies they face. Environmental variables included market dynamism, labor market globalization, and technological change. The hypotheses proposed that the intensity of key talent management would be higher as market dynamism increases, as the degree of labor market globalization increases, and as the degree of technological change increases. Additionally, hypotheses were proposed that firms pursuing an analyzer strategy would employ more key talent management practices than those pursuing a defender strategy, and that firms pursuing a prospector strategy would employ more such practices than those pursuing an analyzer strategy. To test these hypotheses, Tobit regression analysis was conducted using data on large domestic manufacturing firms from the first wave of the Human Capital Corporate Panel survey collected by the Korea Research Institute for Vocational Education and Training in 2005. The results strongly supported all hypotheses except the one predicting that market dynamism would affect the intensity of key talent management. However, regarding competitive strategy, no significant difference was found in the intensity of key talent management between firms pursuing an analyzer strategy and those pursuing a defender strategy. Based on these analytical results, the theoretical implications and future research directions of this study were discussed.