Organizations have adopted Enterprise Architecture (EA) for managing their IT-landscape and ensuring coherence among projects and activities. There is much work about approaches, methods, and tools for EA based on the assumption that their use will create business value. However, the failure of many EA efforts results in the need to investigate the factors influencing EA failure in practice. In this paper, we used a literature review to identify ten EA failure factors. Then we employed the grey-DEMATEL method to explore and analyze the influence of the ten EA failure factors based on the input of five EA experts. The result shows that failure factors are not in isolation, and they can be divided into either causal or effect factors. The factors do not have equal importance but differ in the levels of influence. For the causal factors, the ranking from most to least important is the inability to handle complexity, lack of proven EA methodology, lack of EA knowledge, lack of communication, and lack of tools. For the effect factors, the factors are a lack of support, too high effort, lack of motivation, parallel processes, and unused artifacts. We recommend practitioners to pay more attention to the five causal factors in their EA efforts. Further research is needed to generalize the findings, to understand the dependencies among factors, and to take into account situational dependency of EA failure.