There is paucity of study on predictors of myasthenic crisis (MC), prolonged ventilation and their outcome, a reason why this study was undertaken. Sixty-four patients with myasthenia gravis (MG) were included whose median age was 45 (6-84) years. Their clinical treatment, presence of thymoma, anti-acetylcholine receptor antibody (AchRAb), thymectomy, comorbidities, offending drugs and occurrence of MC were noted. Patients needing prolonged ventilation (>15 days) were noted. Hospital mortality, MG quality of life (QOL) at discharge and thereafter annual hospital visit, admission, expenditure and work day loss were enquired. Fourteen (21.9 %) patients had MC within 1-120 (median 8.5) months of disease onset within a median follow-up of 48 (3-264) months. The precipitating factors were infection in six, surgery in five, tapering of drugs in two and reaction to iodinated contrast in one patient. Male gender, bulbar weakness, AchRAb, thymoma, surgery and comorbid illnesses were related to MC. Eight of them (57.1 %) needed prolonged ventilation. Half the patients with MC had recurrent crisis (2-4 attacks). Death was not related to MC although MC patients had worse QOL, higher annual treatment expenditure with frequent hospital visit and hospitalization. In conclusion, association of comorbid illness with MC and prolonged ventilation highlights the need of close follow-up and appropriate management.