The morphological evaluation of the lung is important in the clinical evaluation of pulmonary diseases. However, the disease process may primarily result in change in pulmonary function without changing pulmonary structure, especially in its early phase. In such cases, the traditional imaging approaches to pulmonary morphology may not provide insight into the underlying pathophysiology. Therefore, we try to assess pulmonary diseases and functions utilizing not only nuclear medicine but also computed tomography (CT) and magnetic resonance imaging (MRI) with various technical approaches. Moreover, positron emission tomography (PET) with new tracers is going to be available within the next decade, which is being tested for demonstrating its clinical relevance in radiology and pulmonary medicine. In this chapter, we overview the state-of-the-art methods and future direction of: (1) ventilation imaging, (2) perfusion imaging, and (3) biomechanics evaluation as pulmonary functional imaging. We also discuss the potential challenges in future pulmonary functional imaging.