Most of the spelling error analysis has been conducted in Latin orthographies and rarely conducted in other orthographies like Arabic. Two hundred and eighty-eight students in grades 1-9 participated in the study. They were presented nine lists of words to test their spelling skills. Their spelling errors were analyzed by error categories. The most frequent errors were phonological. The results did not indicate any significant differences in the percentages of phonological errors across grades one to nine. Thus, phonology probably presents the greatest challenge to students developing spelling skills in Arabic.