This study aims to investigate the differential item functioning (DIF) based on gender and country (Oman/ Other GCC) for verbal ability test in the second level of Gulf Multiple Mental Ability Scale (GMMAS) using Mantel-Haenszel (MH) and the Transformed Item Difficulty (TID) methods. The test consists of 30 multiple-choice items with four alternatives. The study sample consists of archival data for students of the third and fourth grades in GCC countries in the 2009/ 2010 academic year, which was 4280 students. DIF was investigated using MH in SPSS program and the TID using Excel. Kappa coefficient and agreement ratio were calculated to determine the percentage of agreement between the two methods in discovering DIF. The results of the study showed that 60% of items in the verbal ability test for the second level of the GMMAS scale showed DIF related to gender using MH. Similarly, 60% of items showed DIF related to country using MH. However DIF values were small indicating weak DIF in most items. Results also indicated that DIF using TID was found with 30% of items related to gender, and 33.33% related to country. Furthermore, Kappa coefficient (0.524) was moderate between MH method and TID for gender and the agreement ratio was 70%. Kappa coefficient (0.158) was weak between MH method and TID for country and the agreement ratio was 46.67%.