Thoraco-abdominal asynchrony is often observed in many respiratory disorders and/or respiratory muscle dysfunctions and clinically assessed as a sign of respiratory distress and increased work of breathing. This review describes the assessment of thoraco-abdominal asynchrony by respiratory inductance plethysmography. Visual inspection of the Konno-Mead plot yields information about the relative contribution of the RC and the ABD to respiration and about respiratory muscle dysfunction in selected patients. The monitoring of thoraco-abdominal asynchrony is a useful, non-invasive indicator of respiratory muscle load or respiratory muscle dysfunction and can be used to determine response to therapy in individual patients. The technique is limited by the fact that it does not detect respiratory muscle fatigue and that the occurrence of TAA does not always correspond to a clinically relevant respiratory problem, especially in the neonatal period.