This study was designed to investigate potential reading differences between low-achieving and typically achieving first-grade Korean-speaking children by (1) comparing their speed of lexical access on alphanumeric and non-alphanumeric tests of rapid automatized naming and (2) comparing relationships between the two groups' performance on alphanumeric and non-alphanumeric tasks with their performance on component measures of reading. Twenty-seven low-achieving readers and 34 typically achieving readers participated in this study. The low-achieving readers performed significantly more slowly than their typically achieving reading peers on the four measures of rapid naming. The response rates for both alphanumeric naming tasks (digits and letters) showed strong negative correlations with oral reading fluency, while their response rates for the non-alphanumeric naming tasks (Color and Object naming) showed relatively weak relationships with reading measures for both groups. In regression equations, Letter naming tasks were uniquely associated with both word recognition and oral reading fluency. The utility of using alphanumeric naming tasks as indicators for identifying Korean Hangul readers who are at risk for reading disabilities is discussed.