The brain uses more energy than any other human organ, accounting for 20 % of the body's total demand. Mitochondria are energy-converting organelles with a pivotal role in meeting the energetic needs of the human brain. Therefore, the decline of these cellular powerhouses can have a negative impact on the function and plasticity of neurons and is believed to have a prominent role in ageing and in the occurrence of several neurological disorders, such as Parkinson's disease (PD). As a consequence of their physiological roles, mitochondria are subjected to high levels of stress and have therefore developed several stress-protective mitochondrial quality control mechanisms that ensure the optimal activity of their molecular machinery. Here, we review some of the most recent advances in our understanding of the regulation of mitochondrial stress pathways with particular emphasis on how defective mitochondrial quality control might contribute to PD.