Background <p>Abdominal and retroperitoneal sarcomas are rare but prognostically relevant tumors that pose significant diagnostic challenges due to their size and proximity to critical anatomical structures. Cross-sectional imaging is crucial for detection, characterization, staging, and treatment planning.</p> Objective <p>To present the current standards of cross-sectional imaging and to convey relevant aspects for radiological assessment based on established guidelines.</p> Methods <p>Summary of the morphological characteristics, recommendations for imaging and resectability criteria based on current guidelines and published literature.</p> Results <p>Magnetic resonance imaging (MRI) and computed tomography (CT) are indispensable for the assessment of abdominal and retroperitoneal sarcomas, especially with regard to organ and vessel relationships. MRI offers significant advantages over CT in the pelvis and for functional analysis. Typical patterns such as fat content, dedifferentiated areas, or infiltration support entity assessment and therapy planning.</p> Conclusion <p>Standardized, guideline-based imaging is essential for diagnosis, treatment planning, and follow-up care and should be performed in interdisciplinary sarcoma centers.</p>