Problem statement: Writing an essay is a most difficult creative work and consequently requires detailed instruction. There are in fact two types of instruction that contribute to the development of writing skills: Reading activities analysing texts in content and schematic structure to find out how they are composed and process writing activities. The reading activities in Turkish textbooks are thought to be insufficient in this aspect, and although process writing is adopted, it is not put into practise with such activities as writing on the text read or a proverb giving students a list of writing rules. Purpose of Study: This study aims to determine the effect of process writing activities on the writing skills of prospective Turkish teachers as well as to equip them with the writing strategies to apply when teaching writing and to propose several activities in this context. Methods: One-group pretest-posttest experimental design was used. Thirty-four first-year students at Istanbul University Education Faculty Turkish Department taken as sample wrote essays as pretest on a topic of their choosing from a presented list. They were then asked to write essays on the same topic as posttest after a 24-lesson process writing instruction. The pretests and posttests were evaluated by three experts using the "Writing Assessment Rubric" developed from the criteria for assessing written texts in the field and the activities done in the class as a base. The Cronbach's alpha reliability factor is found to be 0.953 for the rubric. The students were also asked to answer a questionnaire with open-ended questions to support the research in a qualitative aspect. Findings and Results: The results of paired samples t-test are found significant at (p<0.01) level in all writing skills constituting "Writing Assessment Rubric". Conclusions and Recommendations: The activities are especially important for prospective Turkish teachers since in addition to improving their writing skills, they also learn how to teach writing. In the questionnaire the students claimed that they learned a planned method of writing, they could understand and evaluate the texts more easily analysing how they have been written, they gave more importance to title, unity, and coherence and they knew what to write and how to write. One student's comment, "I have learned to look not only at the texts I read but also at current events from different perspectives", indicates that process writing also improves thinking.