An emerging theme in professional development for adult literacy program staff over the past decade has been the topic of learning disabilities (LD). As adult educators have come to recognize that the effects of LD can play a significant role in the performance and retention of adult learners, many have sought answers to the following questions: What are learning disabilities, and how do they affect adult learners? How can individuals determine which learners have LD? What strategies are most effective for teaching someone with LD? Interest in what it means to provide effective services for adult learners with LD has not always been this keen. This review was based on ninety-eight references published between 1989 and 2000 as well as selected references published prior to 1989 that supported background information. This literature review organizes the information into two broad categories: what individuals know about adults with LD and how they serve adults with LD. The research reviewed herein has direct implications for how the adult literacy field defines its services. (Contains 1 note.) [Chapter 3 in: Annual Review of Adult Learning and Literacy. Volume 3; copublished with John Wiley & Sons, Inc.; see ED478329.]