BACKGROUND: The difficulties of language rehabilitation in jargon aphasia are well known. The presence of fluent, empty, often neologistic speech makes these clients largely unintelligible, and lack of awareness of their language problems often makes them resistant to therapy. In some clients, writing, although impaired, differs from speech. Neologisms do not occur and output is monitored. Studies have shown that these residual writing skills can respond to therapy, and act as an alternative form of communication. CLIENT: MA has undifferentiated jargon aphasia. Her spoken output had not responded to treatment, and therapy had failed to establish a nonverbal mode of communication. Her writing was impaired, and its slow and effortful execution hindered her progress. However, she retained some ability to access written words and was aware of her errors. AIMS: Therapy aimed to improve access to written words, and to facilitate writing by using a Lightwriter. METHODS AND PROCEDURES: Three stages of therapy were conducted. Words selected by MA for their usefulness were treated. In stage 1 solving anagrams, copying, delayed copying, and written naming were used to improve access to their orthographies. Written naming improved but only to the pictures used in therapy. In stages 2 and 3 further words were introduced, and steps taken to encourage generalisation. In stage 2 several different pictures of each item were used to overcome the picture-specific effect. In stage 3 written words were used to describe situations and answer questions in order to encourage their use in communication. OUTCOMES AND RESULTS: MA improved significantly in writing treated words, and her rate of acquisition accelerated as therapy progressed. Performance was largely maintained after periods without treatment or exposure to the treated items. MA made progress in using her written vocabulary to answer questions in therapy, but needed prompting to use the Lightwriter rather than speech and rarely made functional use of it outside the clinic setting. CONCLUSIONS: MA's progress demonstrates the potential for treating writing in jargon aphasia. Her progress in accessing word orthographies allowed her to use the Lightwriter for communication. Her inability to use writing spontaneously suggests that further therapy is needed and that it should include a regular partner to encourage functional use.