Tendency to industrial clustering at the end of the twentieth century was a turning point in industrial development programs in most countries of the world. Industrial clustering is a model of industrial organization, which has entered industrial literature as a new development strategy. Clustering has provided utilization of efficiencies of scale and aggregation as well as efficiencies of collective efforts by creating conditions for competitiveness advantage, economical growth and export development in the international environment. Today, industrial clustering has been considered as a fundamental strategy for economic development and growth in almost all countries of the world including Iran. This paper aims to assess and to explain important factors affecting the competitiveness of industrial clusters. It also shows the relationship among these factors together. The proposed study uses fuzzy DEMATEL technique; hence, the affecting factors of competitiveness of industrial clusters in the automotive cluster in one of the provinces of Iran is investigated and the importance of each of these factors and their relationships are identified.