This study tested the Double-Deficit Hypothesis (Wolf & Bowers, 1999) that rapid naming deficits and phonological awareness deficits are separate core deficits independent of each other and students exhibiting deficits in both cognitive processing areas would be the most severely impaired in entry-level reading ability. Specifically, this study investigated the contribution of deficits in rapid naming and phonological awareness separately and in combination to entry level basic reading skills of first grade students in rural low-wealth communities. Measures of phonological awareness, rapid naming, and reading achievement were administered to 126 first grade students in two rural school districts. Deficit subgroup comparisons indicated that students with deficits in rapid naming and phonological awareness existing co-morbidly were the most severely impaired in entry level basic reading skills. These results suggest that students who struggle the most with early reading skills may be those who are impaired in these two critical domains of early reading ability. The results of this study partially support the double-deficit hypothesis, and have implications for early identification and early intervention.