Introduction: The use of self efficacy has been suggested as an effective classroom intervention procedure. The present research examined the use of self-efficacy training on the writing of Spanish elementary student with learning disabilities. Objectives: We present a research study focused on the improvement of the writing product and the writing processes fostering self-efficacy in writing. We assessed pre and post results, comparing an experimental and a control group of students with LD. The question is whether we can improve, through a writing self-efficacy intervention, not only the writing product but the processes involved, and their relationship. Method: In total 60 students participated. These students were placed in either the experimental or control group. Two writing samples were evaluated. The four major components of self-efficacy were taught to the experimental group. Results: The results show improvement, not only in the process, but in the product of writing (productivity, coherence, structure and quality) in the experimental group, and in the relationship of process and product in the experimental group but not in the control one. Discussion: More instructional and experimental studies are required to confirm the nature of the process-product relationship in writing. The benefits of employing process product model of writing appears warranted. (Contains 2 tables.)