This article describes the development and validation of the "Learning Difficulties Assessment" (LDA), a normed and web-based survey that assesses perceived difficulties with reading, writing, spelling, mathematics, listening, concentration, memory, organizational skills, sense of control, and anxiety in college students. The LDA is designed to (a) map individual learning strengths and weaknesses, (b) provide users with a comparative sense of their academic skills, (c) integrate research in user-interface design to assist those with reading and learning challenges, and (d) identify individuals who may be at risk for learning disabilities and attention-deficit/hyperactivity disorder (ADHD) and who should thus be further assessed. Data from a large-scale 5-year study describing the instrument's validity as a screening tool for learning disabilities and ADHD are presented. This article also describes unique characteristics of the LDA including its user-interface design, normative characteristics, and use as a no-cost screening tool for identifying college students at risk for learning disorders and ADHD. (Contains 5 tables and 4 figures.)