Extracorporeal life support (ECLS) is a mainstay of current practice in severe respiratory, circulatory or cardiac failure refractory to conventional management. The inherent complexity of different ECLS modes and their influence on the native pulmonary and cardiovascular system require patient-specific tailoring to optimize outcome. Echocardiography plays a key role throughout the ECLS care, including patient selection, adequate placement of cannulas, monitoring, weaning and follow-up after decannulation. For this purpose, echocardiographers require specific ECLS-related knowledge and skills, which are outlined here.