Fusarium crown rot (FCR) caused by Fusarium pseudograminearum (Fp) is an important disease of wheat and barley. FCR can cause significant yield losses and reduce grain quality in many countries, including Australia. To examine population dynamics of this pathogen, 18 locations covering wheat-growing regions in Western Australia (WA) was surveyed in 2008 and 2015. An intensive sampling was conducted in two of the sites (Tammin and Karlgarin) with moderate to high FCR disease incidence. Survey results revealed significant increase in Fp frequency over the 7=year period. Over 86 % of fungi isolated in 2015 were Fp compared with over 58% in 2008. To assess mating type idiomorph composition, trichothecene chemotype and population genetic structure, selected Fp isolates from 2008 (n= 135) were compared with those from 2015 (n=165). These analyses revealed a shift from MAT1-1 in 2008 towards MAT1-2 mating type in 2015 and this was particularly evident in the two intensively sampled sites, Tammin and Karlgarin. A chemotype-specific PCR assay indicated that over 95% of Fp isolates show the 3ADON trichothecene chemotype. Additionally, seven isolates that showed 15ADON chemotype were identified for the first time in Australia. The population genetic structure of 300 isolates was determined using 21 cleaved amplified polymorphic sequences markers and revealed a shift in genotypic diversity, increasing between the 2008 and 2015 populations. This study, which examined FCR population dynamics, mating types, chemotypes, and genotypic structures in WA, will contribute to the management of this important cereal disease in Australia.