Grey mould has been detected on Salicornia bigelovii Torr plants in nursery and in the wild in north-west Mexico. Sampling of the grey mould was performed in the state of Sonora, Mexico, of wild as well as cultivated S. bigelovii plants. The samples were isolated, and based on morphology, the species was identified as Botrytis cinerea Pers. Koch's postulates were fulfilled by pathogenicity tests carried out in plated petri dishes on branches from the 3-month-old potted S. bigelovii plants. To our knowledge, this is the first report of the isolation and identification of the fungal pathogen B. cinerea from S. bigelovii in the north-west Mexico. © 2013 Blackwell Verlag GmbH.