The aim of this study is to investigate the role of early postoperative CT texture analysis in aneurysm progression. Ninety-nine patients who had undergone post-endovascular aneurysm repair (EVAR) infra-renal abdominal aortic aneurysm CT serial scans were enrolled from July 2014 to December 2019. The clinical and traditional imaging features were obtained. Aneurysm texture analysis was performed using three methods-the grey-level co-occurrence matrix (GLCM), the grey-level run length matrix (GLRLM), and the grey-level difference method (GLDM). A multilayer perceptron neural network was applied as a classifier, and receiver operating characteristic (ROC) curve analysis and area under the curve (AUC) analysis were employed to illustrate the classification performance. No difference was found in the morphological and clinical features between the expansion (+) and (−) groups. GLCM yielded the best performance with an accuracy of 85.17% and an AUC of 0.90, followed by GLRLM with an accuracy of 87.23% and an AUC of 0.8615, and GLDM with an accuracy of 86.09% and an AUC of 0.8313. All three texture analyses showed superior predictive ability over clinical risk factors (accuracy: 69.41%; AUC: 0.6649), conventional imaging features (accuracy: 69.02%; AUC: 0.6747), and combined (accuracy: 75.29%; AUC: 0.7249). Early post-EVAR arterial phase-derived aneurysm texture analysis is a better predictor of later aneurysm expansion than clinical factors and traditional imaging evaluation combined. Abdominal aortic aneurysm (AAA) is a prevalent irreversible cardiovascular disease with a high mortality rate that needs immediate surgical intervention. Endovascular aortic aneurysm repair (EVAR) is the preferable choice for patients with AAA as a minimally invasive procedure, but intensive surveillance is recommended to detect possible postoperative aneurysm sac enlargement, the most recognised indicator of AAA rupture 1 , and for which secondary intervention is often performed to prevent deadly progression 2,3. Computed tomography (CT) is commonly used after EVAR for follow-up surveillance, and enhanced CT is usually performed as the first postoperative imaging modality to evaluate the outcome of EVAR surgery and make further individual treatment plans 1,4. Endoleak can easily be observed on postoperative CT and is detected in nearly 32% of AAAs 5. A classic sign of an endoleak is the observation of contrast agent overflow out of the stent-graft. Nevertheless, the long-term significance of the first noticed endoleak is debatable, transient endoleaks can be resolved spontaneously without medical intervention 6,7. Additionally, late-onset endoleaks are typically detected 6 months later after EVAR and are usually occult on the first CT scan 8,9. Thus, the detection of endoleaks on the first operative CT alone is limited to guide clinical decisions, and periodic imaging follow-up is still needed to monitor the evolution of AAA 10 , thus raising the medical expenditure, ionisation radiation, and potential harm to renal function.