Background: Placenta accreta spectrum (PAS) disorders are associated with significant maternal morbidity, making antenatal diagnosis essential for appropriate obstetric planning. Ultrasonography, including grayscale and colour Doppler assessment, is the primary imaging modality for evaluating pregnancies at risk. Aim: To evaluate the role of ultrasonography in detecting PAS disorders and assess the diagnostic performance of individual ultrasound markers and the Placenta Accreta Index (PAI). Methods: This hospital-based cross-sectional observational study was conducted in the Department of Radiodiagnosis over 18 months and included 40 pregnant women suspected of having PAS. Transabdominal and, where required, transvaginal grayscale and colour Doppler ultrasonography were performed. Ultrasound findings and PAI were recorded. Intraoperative findings and/or histopathology served as the reference standard. Diagnostic performance was assessed using sensitivity, specificity, predictive values, accuracy and receiver operating characteristic analysis. Results: PAS was confirmed in 34 (85.0%) participants and was not confirmed in six (15.0%). Among grayscale markers, myometrial thinning (82.4%), loss of the retroplacental clear zone (76.5%) and placental lacunae (67.6%) were frequent findings in confirmed PAS. Among Doppler markers, subplacental hypervascularity (67.6%), turbulent lacunar flow (64.7%) and bridging vessels (61.8%) were commonly observed. Overall ultrasonography demonstrated 94.12% sensitivity, 83.33% specificity, 96.97% positive predictive value, 71.43% negative predictive value and 92.50% accuracy. Mean PAI was significantly higher in confirmed PAS than in non-confirmed cases (4.43 ± 2.47 versus 1.50 ± 1.60; p=0.007). PAI also differed significantly across FIGO grades (p=0.002). For predicting PAS, PAI showed an area under the curve of 0.848. Conclusion: Grayscale and colour Doppler ultrasonography demonstrated high diagnostic accuracy for PAS. PAI was associ