This paper analyses the determinants of travel mode choice for suburbanised commuters in Barcelona, Spain. After describing the importance of residential suburbanisation and the parallel increase in the share of private car use by commuters into the city centre, a nested logit model of transport mode choice is estimated. The results reveal low elasticities, particularly in the case of car commuters. Values of travel time savings are high, although within the ranges obtained in the literature. It is observed that continuing suburbanisation will result in increasing the market share of rail at the expense of the private car use and, mainly, the bus, provided that accessibility to the public transport network is maintained at present levels.