The importance of physical activity to promote health is not new. However, the importance of physical activity in people with neurological conditions is increasingly being recognised. With many of the consequences of neurological conditions including difficulties with mobility, balance and strength; it stands to reason that optimising physical activity levels can result in many physical benefits. Physical activity can have many other flow-on effects with benefits seen in reduced mortality, and enhanced community participation and quality of life (Gordon et al., 2004). We are yet to understand the full extent to which physical activity contributes to rehabilitation outcomes; however, there is a growing body of research highlighting that the intensity of activity within rehabilitation environments is often inadequate for therapeutic gains (Kuys, Brauer, & Ada, 2006; McClanachan, Gesch, Wuthapanich, Fleming, & Kuys, 2013; Polese, Scianni, Kuys, Ada, & Teixeira-Salmela, 2014). It is not surprising therefore, that levels of physical activity continue to be poor following reintegration into the community (Morris, MacGillivray, & McFarlane, 2014). It is important that, as health care professionals, we support and encourage physical activity in all our clients. To that end, this special issue of Brain Impairment is devoted to raising the issue of physical activity in people with neurological conditions, and addressing questions such as: Why is physical activity important? How do we measure it? How do we enhance it, and what are the benefits of increased activity? This special issue brings together experts from around the world investigating and promoting physical activity across the continuum of care in various neurological populations including stroke, traumatic brain injury, multiple sclerosis and Parkinson's disease.