Background: There are limited data on the characteristics, incidence, and mortality of patients with myasthenia gravis (MG) admitted to the ICU. Aims: To study the epidemiology, characteristics and outcome of patients with MG in Australian and New Zealand (ANZ) ICUs over a decade. Methods: We performed a retrospective observational, cross sectional study of data from the Australian and New Zealand Intensive Care Society (ANZICS) Adult Patient Database (APD). We collected data on all adult patients admitted with a primary diagnosis of MG to 159 Australian and 19 New Zealand ICUs between January 1, 2005 and December 31, 2015.We extracted detailed relevant data and performed statistical assessment. Results: We identified 245 patients admitted to ICU with the primary diagnosis of MG, with an incidence increasing from 1 to 2.5 per thousand ICU admissions (P < 0.0001) and from 1 to 2.2 per million people (P = 0.02). Mean age was 60 years with more patients being female (53.7% vs 47.3%) and 91 (37.1%) patients received mechanical ventilation. Hospital mortality occurred in 13 (5.3%) patients with a mortality rate lower than in other ICU patients. Conclusions: In ANZ, the ICU and population incidence of MG has increased over the last decade. However, its mortality rate was low.