Attention is correlated with reading, but the extent to which behavioral ratings and sustained attention relate to reading skills is unclear. We assessed 245 fourth and fifth grade struggling readers (mean age = 10.3 years) on behavioral ratings of attention, sustained attention, and reading over a school year. Contributions of behavioral ratings and sustained attention were considered cross-sectionally and longitudinally in the context of other important predictors of reading. Results suggest that sustained measures and behavioral ratings assess distinct, yet overlapping, aspects of attention. Both types of attention accounted for unique variance in comprehension, but not word reading accuracy or fluency, when evaluated cross-sectionally. Results also support the role of behavioral ratings of attention in fluency and in comprehension growth. Findings suggest that multidimensional assessment of attention is useful when considering its relation to reading, and highlight the need to integrate conceptualizations of attention that arise from different theoretical approaches.