Background: The term learning disability applied to explain the problems of a person with average intelligence in basic academic skills and can affect a person's ability to understand and use spoken or written language, mathematical calculations, coordinate movements, or direct attention. Learning disability can be divided into three difficulties in reading, writing, and arithmetic. The prevalence of learning disability in recent years significantly increased and in several studies, it has been various estimates.

Conclusion: One of the main reasons for the significant differences in the prevalence of this disorder in several studies is different diagnostic approaches. Three approaches in diagnosis learning disabilities are inconsistencies between achievement-ability, response to intervention, and cognitive processing approach. Each of these approaches has their own supporters and opponents. Thus, in this paper, in addition to the overview of definitions and descriptions of Learning disability, various diagnostic approaches are discussed in detail and the final conclusions are done.