Imaging plays a pivotal role in the post-operative management of renal transplant patients, essential for monitoring graft status and enabling the early diagnosis of complications. This chapter provides a comprehensive review of the key imaging findings associated with post-renal transplant complications, categorized into parenchymal, vascular, and urologic issues. Ultrasound is the primary imaging modality due to its accessibility and utility, supplemented by other techniques such as computed tomography or magnetic resonance imaging. Parenchymal complications, including acute tubular injury, rejection, and drug toxicity, often present with non-specific imaging findings, frequently necessitating a biopsy for definitive diagnosis. However, imaging is crucial for narrowing the differential diagnosis and determining the need for a biopsy. Vascular complications, such as transplant renal artery stenosis, thrombosis, arteriovenous fistulas, and pseudoaneurysms, can be a serious cause of graft failure. Doppler ultrasound is critical in these cases, providing decisive information on hemodynamic changes. Urologic complications commonly include urinary obstruction and peritransplant fluid collections (hematomas, urinomas, and lymphoceles), for which imaging is essential to identify the cause and type. Additionally, the imaging findings of rare complications like post-transplant lymphoproliferative disorder are also discussed. In conclusion, a thorough understanding of the clinical features and timing of various post-transplant complications, combined with proficient interpretation of characteristic findings on different imaging modalities, is vital for improving graft survival and patient outcomes.