Enterprise architecture (EA) is widely employed to reduce complexity and to improve business–information technology (IT) alignment. Despite the efforts by practitioners and academics in proposing approaches to smoothen EA development, it is not easy to find a fully successful EA. Because EA development is a complex endeavour, it is important to understand the obstacles that practitioners face during EA development. With the grounded theory, we studied how obstacles during EA development emerged from practitioners’ point of view in 15 large enterprises. The study identifies lack of communication and collaboration as the core obstacle that can explain many other obstacles. Communication and collaboration were also harmed by other perceived EA development obstacles, including lack of knowledge and support inside organization and issues imposed by external parties, hesitation in training personnel, setting too ambitious goals, constant change of management, (lack of) clarity in EA development process, lack of budget, forcing personnel to adopt EA, lack of motivation, organizational culture, and organizational structure deficiencies. The lack of communication and collaboration caused several undesired effects to organizations, such as being unable to set common goals and achieve a shared understanding, personnel’s distrust, endangered EA governance, lack of innovation capability, lost competitive edge, and ineffective EA outputs. The study highlights that organisations should improve their communication and collaboration before embarking on EA to encounter fewer obstacles. We provide four recommendations for practitioners to improve communication and collaboration in EA development.