We studied the compositional written skills and spelling competence of individuals with a severe hearing impairment, examining qualitative and quantitative characteristics of their texts, the psycholinguistic variables modulating their productions, and writing errors following a fine-grained analysis. Sixteen deaf young adults, educated in bilingual settings, were examined and compared to a group of control hearing subjects matched for gender, age, and education. Writing skills were examined through both written composition and written picture-naming tasks. Concerning compositional skills, deaf participants produced shorter and less informative texts, with fewer adjectives and subordinates, and were qualitatively worse with respect to texts produced by hearing controls. Words produced by deaf participants were those acquired earlier and facilitated by a higher lexical neighbourhood. Errors were mainly semantic, morphological, and syntactic errors, reflecting general linguistic weakness. Spelling errors were few, with phonologically nonplausible misspellings relative to controls, and with phonologically plausible ones being quite rare. In the picture-naming task, deaf people had a greater number of all types of errors with respect to their text, including semantic and morphological errors. Their spelling performance featured mainly phonologically nonplausible misspellings, while phonologically plausible ones were relatively few and comparable to controls. Overall, the writing of deaf adults reveal limitations in grammar and lexical-sematic linguistic competence. This was associated with spelling deficits characterized mainly by the poorer use of phonological sublexical spelling procedures. However, in an ecologic context, their spelling deficits appear not so important as has been claimed in the literature.