The present study aims to teach writing to deaf students, through conditional discriminations. The teaching procedure was applied with educational software adapted for insertion of sign language videos, as well as of images, syllables, words, phrases and sentences for the deaf students and had sentences as teaching unit. Three deaf students of High School from Sao Paulo, Brazil, participated. Sentences with LIBRAS (A), images/ scenes that represented the sentences (B), and printed sentences (C) were part of the teaching procedure. The repertoire before and after the teaching procedure and the writing generalization were evaluated. Comparing the previous performance with the one presented after the teaching procedure, it was verified that the students wrote sentences with grammatical elements (as article, noun, verb, preposition). The results showed that the procedure was effective to enlarge the writing repertoire of deaf students.