There is considerable interest in the contribution that workplace-based mobility management interventions can make to achieving more sustainable mobility patterns. A number of studies have evaluated the impacts of workplace-based interventions on the commuting behaviour of staff, but the broader potential of such initiatives depends on the willingness of employers to support them. Little research has been carried out examining the perspectives of senior managers. The research which has been conducted has focused on employers located in urban or rural areas. This paper reports on in-depth interviews with senior managers of employers located in two peri-urban areas on the edge of the city of Bristol, south-west England. The research was carried out during a period when public funding was available to support the introduction of sustainable transport measures. The interviews aimed to find out whether senior managers perceived the promotion of sustainable transport as relevant to their business concerns, and how this varied between different types of organisation. The results showed that all managers believed that measures to increase the use of alternative modes for commuting and local business travel could be beneficial for their business, even if these benefits were indirect and difficult to quantify. The perceived benefits of sustainable transport included: helping to ease traffic congestion on the road network, thereby reducing associated delays and stress; helping employers manage excessive demand for car parking; improving staff wellbeing; and widening the recruitment opportunities among workers lacking access to a private car. Employers who perceived the greatest benefits were also the most willing to engage with public authorities in introducing new workplace-based mobility measures. The findings on employer support for mobility management are relevant not only to peri-urban areas but also to employment sites within other areas (in particular suburban areas and the rural hinterland) where the same challenges may apply of encouraging alternatives to single occupancy car use without the means to invest in comprehensive public transport.