Theoretical and empirical approaches have stressed the existence of financial constraints in firms' innovative activities. Although a large number of innovation projects are abandoned before their completion, the empirical evidence has focused on the determinants of innovation while failed projects have received little attention. This paper analyses the role of financial obstacles on the likelihood of abandoning an innovation project by using panel data of potential innovative Spanish firms for the period 2005-2013. Our analysis differentiates between internal and external barriers on the probability of abandoning a project and we examine whether the effects are different depending on the stage of the innovation process. Controlling for potential endogeneity, we use a bivariate probit model to take into account the simultaneity of financial constraints and the decision to abandon an innovation project. Our results show that financial constraints most affect the probability of abandoning an innovation project during the concept stage.