Background: The purpose of this in-vitro study was to evaluate the repeatability and interdevice reliability of two identical spectrophotometers with different software. Methods: Twenty-six shade tabs of a shade guide (Vita 3D-Master, Vita Zahnfabrik) were measured with two identical spectrophotometers (Vita EasyShade V) with different software (v509i: Device A; v505p: Device B), and CIELab values were recorded (n=260). The color difference (∆E<inf>00</inf>) values between measurements of spectrophotometers were calculated. For repeatability, the 3M2 shade tab of the same shade guide was measured 50 times with each spectrophotometer. The matching accuracy rate of the devices with shade guide was calculated. Interdevice reliability and differences between devices were calculated using intraclass correlation coefficient (ICC), Cronbach's alpha, and Paired T-test (α=0.05). Results: Interdevice reliability was found to be high for L*, a*, and b* parameters (ICC>0.99). The ∆E<inf>00</inf> values of the shade tabs range from 0.21 to 1.78, which were lower than the acceptability threshold (∆E<inf>00</inf><1.8). The mean L* value of Device A was significantly higher than that of Device B (P<0.001), while the mean a* and b* values were significantly lower (P<0.001). The repeatability is excellent for a* and b* parameters (SD<0.1), however, slightly lower for the L* (0.15<SD<0.25) in both devices. The matching accuracy rates of both devices were calculated as 34.6 %. Conclusion: The reliability and repeatability of two identical spectrophotometers were found to be high, and the color difference values were found to be at an acceptable level. However, both devices can display different L*, a*, and b* values for the same shade guide.