Core stability is a popular term that has evolved into a concept that is the fundamental principle behind many rehabilitation, performance training and preventative programmes. This study examined the evidence behind the concept of core stability by answering key research questions with reference to the quality of evidence available. Based on the available evidence guidelines were created and graded using the Scottish Intercollegiate Guidelines Network (SIGN 50) guideline. Evidence was gathered by using key word searches of electronic data bases and manual/hand searches of contents and reference lists of recent journals and books. Experimental studies and reviews were selected if their contents related to one or more of the key questions. All studies were analysed by an appropriate checklist that considered such factors as methodological techniques and levels of bias. Each study was then considered in terms of being able to contribute to the research question. On review of the checklists appropriate intervention studies were compiled into evidence tables that provided a consistent format to compare studies that related to a specific key question. According to the Guidelines developed by SIGN 50 (2004) each study was given a rating of Evidence Level. On further consideration of the evidence behind the key questions, guidelines were developed that related to the key questions. The guidelines were graded according to the SIGN 50 (2004) criteria. On reviewing the evidence behind the concept of core stability it was found that significant gaps existed in the knowledge base. A major problem was the lack of a universal definition for core stability. This made comparison between different studies difficult or inappropriate. There would appear to be an acceptable number of anatomical, physiological and biomechanical studies to support the concept of core stability however there is currently a serious lack of evidence to support much of the previously accepted or assumed concepts. Of note is the magnitude of empirical research behind the many theories and hypotheses relating to human performance and core stability. The dearth of evidence based core stability concepts and practises mirrors the vast amount of anecdotal, intuitive and subjective application of the concept. Slowly with new research some of the anecdotal practices are being vindicated. In conclusion six guidelines relating to the concept of core stability were created. However more research is required to justify many current practices and to provide evidence on which to base future developments.