This cross-sectional study was conducted with a random sample of 155 K-12 students served in public school settings and established the extent to which students with emotional/behavioral disorders (E/BD) experience academic achievement deficits with attention to age and gender differences. In addition, this study examined particular types of problem behaviors related to academic achievement. Results indicate that students with E/BD showed large academic achievement deficits across all of the content areas, and the deficits appeared to be stable or worsen in the case of mathematics across age. There appeared to be no gender differences. Additionally, externalizing behaviors were related to reading, mathematics, and written language achievement; whereas, internalizing ones were not.