The purpose of the study was to investigate the developmental nature of Arab American children's (second, fourth and sixth graders) acquisition of spelling knowledge. The study addressed the question whether bilingual Arab American children's patterns of spelling development are identifiable as measured by the Schlagal's Qualitative Spelling Inventory. Further, the study examined whether Arab American Bilingual children's spelling performance changed based on their grade level and word-level complexity. Seventy-five students participated in the study (25-second graders, 25 fourth graders and 25 sixth graders). Shlagal's inventory of six spelling lists was administered on two different school days during one week. Two spelling lists were administered at each grade level. One list was given at the level immediately below the class, and another at the grade level. The results of data analysis showed a variance of scores on spelling features presented in the six lists given to second, fourth and sixth graders. The implication of scores variance was due to spelling features difficulty level presented in the second list of each grade level.