Objectives: This study was made to determine the accuracy of 3 intraoral scanners (IOS) on different Endocrown preparations. Methods: Four Endocrown preparations with two internal angulations (6° & 10°) and two depths (3mm & 5 mm) were made on an acrylic typodont. Reference scans were taken with a reference scanner (InEos X5) and saved in a STL format then each IOS (Trios, Omnicam, and My crown) scanned each preparation 8 times. The STL files obtained were compared to the reference scans for measuring (trueness) and within each test group (precision). A reverse engineering software was employed to measure the accuracy of the IOS. Results: Trueness: the best scanner was the Trios scanner (25.13±3.89µ) followed by My crown (37.24±6.8µ) then Omnicam (39.31±6.08µ). There was a statistically significant difference in total trueness of the Trios scanner compared to both My Crown and Omnicam. The 10° (30.87±6.74µ) was significantly higher in trueness than 6° (36.9±8.98µ). The 5mm depth (31.3±6.56µ) was significantly higher in trueness than 3mm (36.48±9.37µ). Precision: the best scanner was the Trios scanner (18.16±4.53µ) followed by Omnicam (26.21±5.24µ) then My crown (30.14±9.92µ). No significant difference in precision between 6° (24.08±8.12µ) and 10° (25.21±9.09µ). Five mm depth (20.24±5.19µ) was significantly higher in precision than 3mm (28.11±9.2µ) Conclusion: Trios scanner shows better trueness and precision than Omnicam and My crown scanners. Endocrown scans with internal angulations 10° show more accurate results than those with 6° scans, and 5mm axial wall showed more accuracy than 3mm axial wall scans.