The Pediatric Examination of Educational Readiness was administered to 386 preschool children to determine whether the predicitive value of this instrument could be enhanced by the inclusion of systematic measures of processing efficiency, selective attention, behavioral adaptation, and neuromaturation. Findings on these dimensions, as well as the traditional developmental attainment measure, were consistent with McCarthy cognitive scores. Concerns regarding developmental attainment, processing efficiency, and selective attention were more common in children later found to have weak kindergarten mastery skills. Data analysis revealed minimal redundancy and specific additive effects in this multidimensional assessment. It is concluded that such instruments can contribute to a broader, more integrated diagnostic procedure for behavioral and developmental problems.