Preprocedural imaging is essential for the safe and effective planning of left atrial appendage (LAA) occlusion. Transesophageal echocardiography (TEE) remains the gold standard, offering real-time visualization of LAA anatomy, thrombus detection, and device sizing. Computed tomography (CT) provides complementary high-resolution 3D assessment and is particularly valuable in patients unsuitable for TEE. Cardiac magnetic resonance (CMR), though primarily used in research, allows noninvasive thrombus detection without radiation or contrast exposure. Each modality has unique advantages and limitations, and their integration can enhance procedural safety and success. This chapter reviews the roles, strengths, and technical considerations of TEE, CT, and CMR in preprocedural planning, including their impact on device sizing, anatomical evaluation, and procedural guidance. Emphasis is placed on tailoring imaging approaches based on patient-specific anatomical and clinical characteristics to optimize outcomes.