This article reports on the effects of a family literacy program for first graders that had three main characteristics: (1) book reading with parents that adapts parental intervention to the child's gradually increasing skills in reading during the school year, (2) support for writing activities, and (3) enjoyable home activities complementing the in-class teaching. The 108 participants were assigned to two treatment conditions: Workshop and Control. Pre- and post-test group comparisons indicate that the workshop program has a positive effect on the children's performance in both reading and writing. Children produced longer texts and used better vocabulary, sentence structure and spelling. This study provides new data supporting the utility of family literacy programs by demonstrating their positive effect on writing. This confirms the importance of connecting reading and writing activities in family literacy at the beginning of learning and that parents should be invited by the teacher to intervene in these two areas rather than only in reading.