Andrew Halestrap is Professor of Biochemistry at the University of Bristol and was the first to demonstrate the existence of specific transporters for monocarboxylates such as lactate and pyruvate across the plasma and mitochondrial membranes. However, he is best known for his studies on the molecular mechanism and role of the mitochondrial permeability transition pore that is now accepted to play a critical role in cell death. The widely accepted molecular mechanism for this pore was first proposed by him and he has subsequently provided extensive evidence to support this important concept. He also pioneered studies on the role played by the MPTP in reperfusion injury, and the extent of MPTP opening is now recognised as a major determinant in the recovery of the heart and brain from ischaemia. He was the first to demonstrate protection of both the heart and brain from reperfusion injury by inhibitors of MPTP opening, and has subsequently identified a range of protective regimes involving inhibition of pore opening that are leading to improvements of the cardioplegic solutions and perfusion protocols used in cardiac surgery.