The aim of this article is to provide an overview of symptoms, causes and diagnosis of Dyscalculia based on current research findings.This paper reviews selected literature spanning from 2001 to date from PubMed, PsycINFO, Springer, ERIC databases using the keywords: dyscalculia, mathematical disability and math disorder and selectively reviewed articles for the diagnostic of Dyscalculia in general. The acquisition of mathematical skills is a development process that begins well before school starts. As a result, the children already start with different mathematical prior knowledge in the initial class. In order to be able to identify children at risk for a weakness in arithmetic (technical term: dyscalculia) at an early stage and to adequately support their needs, it is essential to set up a well-functioning diagnosis. According to the International Classification of Diseases (ICD-10), Dyscalculia belongs to the specific developmental disorders and is characterized by impairment in speech, motor activity and visual-spatial perception. The discrepancy between intelligence and expected arithmetic abilities is the essential criterion for the diagnosis of Dyscalculia. A comprehensive examination, also suitable for therapeutic intervention preparation, should take etiological conception of Dyscalculia into account as well as impairments in visual information processing. This should be reflected in the deliberate selection of appropriate test procedures. Recent diagnosis of Dyscalculia does not only account the classroom-based math performance and IQ into account, but also impaired basic skills associated with Dyscalculia into account while IQ discrepancy and appropriate IQ test for Dyscalculia remain a controversial topic. An innovative aspect of this work is synthesizing comprehensive view of Dyscalculia