In this paper, we analyse the opinions, attitudes and willingness of consumers to pay for biodiesel as an alternative to diesel in Barcelona province. Data were gathered from face-to-face structured questionnaires from 300 diesel car owners/users that regularly purchase fuel. A variation of the traditional choice experiments (CE) was used by excluding the price attribute from the design. In a subsequent contingent valuation (CV) exercise, respondents were asked to state their maximum willingness to pay (WTP) for their preferred choice sets using the "payment card" format. The relative importance of the attributes and levels were calculated by estimating a random parameter logit model. The results demonstrated, contrary to the literature in Spain, that consumers were not willing to pay for biodiesel, especially when its production may negatively affect food prices. The main limitation was that car manufacturers do not recommend its use as it may lead to engine failure. The public authorities are asked to work jointly with the automotive industry to address this drawback. (C) 2015 Elsevier Ltd. All rights reserved.