Background and Aim: The quick speech in noise (Q-SIN) test results have been reported to be entirely different in monolinguals compared to bilinguals. We attempted to assess the reliability and equivalency of the Persian Q-SIN test in Azeri-Persian bilinguals.Methods: The Q-SIN test was performed on 51 Persian monolinguals and 51 Azeri-Persian bilinguals by the 1st, 2nd, 3rd, and 5th lists binaurally under headphone. The signal-to-noise ratio (SNR) loss was determined for each group. The reliability was evaluated on 30 bilinguals.Results: There was no gender effect on all results in both groups. The mean SNR losses of four lists were -1.19 and -0.8dB in monolinguals and bilinguals, respectively, also they were within normal limits in both groups. The mean SNR losses for all lists in monolinguals were better than those in bilinguals, but there was a significant difference between two groups for list 1 (p=0.03). No significant differences were observed between two runs for lists 1, 3, and 5 in bilinguals, and two runs for lists 1, 2, and 5 were significantly correlated. There were no significant differences between the scores of lists 2, 3, and 5 in bilinguals (p>0.000), and a moderate correlation existed between lists 2 and 3.Conclusion: The scores of lists 2, 3, and 5 in bilinguals are similar to those in monolinguals. In bilinguals, lists 1 and 5 are reliable, and lists 2 and 3 are equivalent. The overall results indicate limitations in both reliability and equivalency of Persian Q-SIN lists in the bilinguals.