The unique combination of phenotypic manifestations seen in ataxia telangiectasia (AT) has intrigued neurologists, oncologists, radiation biologists and immunologists for several decades. Initially, the primary care givers of AT patients are often pediatricians but neurologists will inevitably become involved in their care. Over the last few years great strides have been made in understanding the genetic basis of this disease but useful therapeutic interventions are still not available. In this article, we review the clinical features and the current understanding of the pathophysiology of the syndrome. In addition, we address issues related to genetic counseling, prenatal diagnosis, screening and implications for AT heterozygotes.