Purpose: The empirical record regarding the expected co-occurrence of attention-deficit/hyperactivity disorder (ADHD) and specific language impairment is confusing and contradictory. A research plan is presented that has the potential to untangle links between these 2 common neurodevelopmental disorders. Method: Data from completed and ongoing research projects examining the relative value of different clinical markers for separating cases of specific language impairment from ADHD are presented. Results: The best option for measuring core language impairments in a manner that does not potentially penalize individuals with ADHD is to focus assessment on key grammatical and verbal memory skills. Likewise, assessment of ADHD symptoms through standardized informant rating scales is optimized when they are adjusted for overlapping language and academic symptoms. Conclusion: As a collection, these clinical metrics set the stage for further examination of potential linkages between attention deficits and language impairments.