The current study employed a meta-analytic approach to investigate the relative importance of component reading skills to reading comprehension in struggling adult readers. A total of 10 component skills were consistently identified across 16 independent studies and 2,707 participants. Random effects models generated 76 predictor-reading comprehension effect sizes among the 10 constructs. The results indicated that six of the component skills exhibited strong relationships with reading comprehension (average rs = 0.50): morphological awareness, language comprehension, fluency, oral vocabulary knowledge, real word decoding, and working memory. Three of the component skills yielded moderate relationships with reading comprehension (average rs = 0.30 and < 0.50): pseudoword decoding, orthographic knowledge, and phonological awareness. Rapid automatized naming (RAN) was the only component skill that was weakly related to reading comprehension (r = 0.15). Morphological awareness was a significantly stronger correlate of reading comprehension than phonological awareness and RAN. This study provides the first attempt at a systematic synthesis of the recent research investigating the reading skills of adults with low literacy skills, a historically understudied population. Directions for future research, the relation of our results to the children's literature, and the implications for researchers and adult basic education programs are discussed.