Although chickpeas are reported to be susceptible to more than 50 pathogens, few diseases are currently recognized as significant economic constraints to production. Ascochyta blight, caused by the fungal pathogen Ascochyta rabiei, is the most serious chickpea disease worldwide. This paper describes the pathogen, symptoms of infection, biological and morphological characteristics, and methods to study the fungus. Accepted for publication 17 November 2010. Published 3 January 2011.