This study evaluated the effects of an intervention program aimed to improve reading and spelling ability through instruction in morphological awareness together with other forms of linguistic awareness, including knowledge of phonology, orthography, syntax, and semantics. Sixteen children aged between 8;07 (years;months) and 11;01 who demonstrated specific spelling difficulties were randomly assigned to either an experimental or a control group. Participants received an average of 19.4 sessions of intervention that focused on increasing awareness of the morphological structure of words, with particular attention to the orthographic rules that apply when suffixes are added to the base word. Participants in the experimental group made significantly greater gains in reading and spelling accuracy than those in the control group on both experimental and standardized measures of reading and spelling. The results also show that participants were able to generalize to new words what they had learned in the intervention sessions. Practitioners should consider the likely benefits of literacy intervention that focuses on developing morphological awareness in conjunction with other types of linguistic awareness.