This brief paper summarizes warning signs of learning disabilities in preschool children, elementary school children, and secondary school children. It notes that learning disabilities are presumed to arise from dysfunctions in the brain resulting in significant difficulties in perceiving information, processing and/or remembering information, and/or in expressing information. For preschool children warning signs are listed in the areas of language (e.g., difficulty learning new words), motor skills (clumsiness), cognition (difficulty with basic concepts), attention (high distractibility), and social behavior (easily frustrated). For elementary school children, warning signs are listed for language/mathematics (consistent reading and spelling errors), motor skills (poor coordination), attention/organization (difficulty finishing work on time), and social behavior (apparent lack of "common sense"). And for secondary school children, warning signs are listed for the areas of language/mathematics/social studies (avoidance of reading and writing), attention/organization (difficulty staying organized), and social behavior (difficulty accepting criticism). (DB)