The purpose of this article is to provide a quantitative synthesis of the empirical literature comparing adults with reading disabilities (RD) and adults without RD across an array of intellectual, academic, cognitive, vocational, and life-adjustment measures. The central question posed by this review is to what extent and in what manner do adults with reading disabilities differ from adults without reading disabilities on measures assumed to relate to overall reading competence. In all, 52 studies met criteria for a meta-analysis yielding 776 effect sizes (ESs). The results revealed that adults with RD varied substantially in ESs from adults without RD on the classification measures (reading comprehension, reading recognition, verbal intelligence).