Students at risk for learning disabilities (LD) are overidentified in elementary schools in Oman due to the absence of adequate instruments which teachers can use in validating their observations. Teachers need valid instruments so that their judgment of students’ behaviours can help in making academic and non-academic decision. The Learning Disabilities Diagnostic Inventory (LDDI) is widely used to examine manifestations of LD as an intrinsic processing disorder. This study aimed to verify the six-factor structure with confirmatory factor analysis, and test its measurement invariance across child gender. Teachers completed the Arabic version of the LDDI for an Omani sample of 1564 children aged 7 to 11. Overall, the six-factor model showed an acceptable fit after performing some post-hoc modifications that were justified on a theoretical ground. Results indicated metric invariance across gender. Zero-order correlations, however, were highly significant, which reflected that the Arabic version of the LDDI showed poor discriminant validity compared to the original LDDI. The Arabic version of the LDDI, however, can be a handy tool to screen for the LD manifestations and help in responding to teachers’ academic concerns about students in Key stages 1 and 2 in Oman.