Arabic is characterized by extensive dialectal variation, diglossia, and substantial morphological complexity. Arabic lacks comprehensive diagnostic tools that would allow for a systematic evaluation of its development, critical for the early identification of language difficulties in the spoken and written domains. To address this gap, we have developed an assessment battery called Arabic Language: Evaluation of Function (ALEF), aimed at children aged 3 to 11 years. ALEF consists of 17 subtests indexing different language domains, modalities, and associated skills and representational systems. We administered the ALEF battery to native Gulf Arabic-speaking children (n = 467; ages 2.5 to 10.92; 55% boys; 20 children in each 6-month age band) in Saudi Arabia in two data collection waves. Analyses examining the psychometric properties of the instrument indicated that after the removal of misfitting items, the ALEF subtests had reliability coefficients in the range from 0.78 to 0.98, and resulting subtest scores displayed a consistent profile of positive intercorrelations and age effects. Taken together, the results indicate that the ALEF battery has good psychometric properties, and can be used for the purpose of evaluating early language development in Gulf Arabic speaking children, pending further refinement of the test structure, examination of gender-related differential item functioning, and norming.