In the Australian wheat belt, periods of moderate to extreme high temperatures at the end of the season frequently reduce grain yield and also impact on end-use quality. With global warming, extreme heat events are expected to become more frequent in the southern Australian wheat belt, making heat stress an increasing concern. Clearly, varieties with improved heat tolerance would be highly desirable. The extent of genetic variation for heat tolerance in Australian durum wheat germplasm is largely unknown and anecdotal evidence suggests that Australian durum wheat varieties may be uniformly heat susceptible. We obtained durum genotypes from various sources and plants were grown at an irrigated field site in NSW in 2011. A late-sown trial was used to expose plants to heat stress during flowering and seed set, and a second trial was sown at the normal time to provide a control. Both trials were flood irrigated to minimize water stress. Observed effects of heat on yield, single grain weight and quality will be presented and a list of potential heat tolerant lines suggested.