This study compared two instructional methods for teaching spelling to elementary students with learning disabilities (LD). Forty-two elementary students with LD were randomly assigned to one of two instructional groups to teach spelling words: (a) a rule-based strategy group that focused on teaching students spelling rules (based on the "Spelling Mastery Level D" program) and (b) a traditional instruction group that provided an array of spelling activities (i.e., introducing the words in the context of story, defining the meaning of the words, sentence writing, and dictionary skill training) to teach spelling words. Daily instructional sessions lasting 30 minutes were conducted for 4 consecutive weeks. Four different word types (i.e., regular, morphological, spelling rule, and irregular) were introduced as instruction progressed. After receiving instruction in one of the instructional groups, the students were compared on scores from unit tests, a standardized test, a sentence-writing test, a transfer test, and a maintenance test. Overall results indicated that the rule-based strategy group using "Spelling Mastery Level D" was more effective in increasing student-spelling performance, particularly for the regular, morphological, and spelling-rule words. The instructional implications of these findings are discussed. (Contains 7 tables.)