Multimorbidity - the simultaneous presence of several chronic diseases - is very common in the critically ill patients. Its prevalence is roughly 40-85 % and continues to increase further. Certain chronic diseases such as diabetes, obesity, chronic heart, pulmonary, liver or kidney disease and malignancy are associated with higher risk of developing serious acute complications and therefore the possible need for intensive care. This review summarizes and discusses selected specifics of critical care for multimorbid patients.