Background: Placenta accreta spectrum (PAS) is a general term used to describe the clinical condition when part of the placenta, or the entire placenta, invades the uterine wall making it difficult to separate. One of the methods to grade this disorder is the International Federation of Gynecology and Obstetrics (FIGO) grading system which helps in determining the nature and severity of PAS disorders. The PAS ultrasound grading was performed via transvaginal and transabdominal ultrasonography (in all cases) according to the guidelines for ultrasonographic (USG) detection of PAS using the following USG signs, loss of clear zone, placenta lacunae, bladder wall disorders, uterovesical hypervascularity, and increased vascularity of the parametrial region. Aim and objective: To determine the relationship between PAS ultrasound score and FIGO clinical grading on the incidence of PAS disorders at H. Adam Malik General Hospital, Medan, Indonesia. Materials and methods: Patient identity and secondary data were obtained from medical records. The PAS ultrasound score data was taken from transabdominal ultrasonography and transvaginal ultrasonography records. The FIGO clinical grading data collection was based on operative field findings. Some sections of the uterus and placenta were submitted to the anatomical pathology laboratory for histopathological examination to assess the involvement of the placenta invading the uterine wall. Finally, the correlation between the FIGO grading and PAS ultrasound score was calculated using SPSS software. Results: The results showed that there was a significant relationship between the length of operation (p = 0.042; p > 0.05); curettage history (p = 0.231; p > 0.05); the amount of bleeding (p = 0.16; p > 0.05); gestational age at delivery (p = 0.384; p > 0.05); upper arm circumference (UAC) (all) (p = 0.295; p > 0.05); parity (p = 0.133; p > 0.05); and history of placenta accreta (p = 0.761; p > 0.05) with PAS score. There was a significant relationship between the amount of bleeding and arterial ligation with a value of p = 0.011 (p < 0.05) where the majority of patients who underwent ligation experienced bleeding of 2000−3000 cc compared to those who did not undergo the ligation procedure with bleeding below 2000 cc. The FIGO score frequency distribution was 17 people (34.7%) at stage I; 14 people (28.6%) at stage II; 9 people (18.4%) at stage IIIa; 6 people (12.2%) at stage IIIb; and 3 people (6.1%) were at stage IIIc. On the contrary, for PAS score found 7 people (14.3%) at stage 0; 22 people (44.9%) at stage I; 16 people (32.7%) at stage II; and 4 people (8.2%) at stage III. The Kolmogorov–Smirnov normality test showed that the PAS score and FIGO score data were not normally distributed (p < 0.05). After conducting the Chi-square test to assess the relationship between the FIGO score and the PAS score, a p-value of 0.000 was found; this value indicates that there is a significant relationship between the PAS score and the FIGO score (p < 0.001). Based on the presence of USG signs of impaired PAS, 57.9% [95% confidence interval (CI): 51.6–64.0%; 150/259] of women were classified as PAS 0, 15.1% (95% CI: 11, 2–19.9; 39/259) as PAS 1, 6.2% (95% CI: 3.8–9.8; 16/259) as PAS 2, and 20.8% (95% CI: 18, 2–26.4; 54/259) as PAS 3. Conclusion: In this study, it was found that there was a significant relationship between PAS score and FIGO clinical grading in the incidence of PAS abnormalities.