After years of research on the effect of feedback provided by peers or teachers on learners writing performance, there is still a need for further investigation in this area. In the present study, a group of learners were observed in the process of an English as a Second Language (ESL) writing course in order to investigate the effect of peer reviewing and tutor conferencing on learners writing performance in their narratives. For this end, an interrupted time-series design (O-X-O-X-O) was employed. It involved an observation of the samples followed by the first treatment; that is, peer feedback followed by a second observation. Then, a second treatment, or tutor conferencing, preceded another observation. Next, two raters were trained to use the Wong Scale (Wong, 1989) to score the stories written by the samples. The scores were tested for their inter-rater reliability, and an acceptable Cronbachs Alpha was observed. The results of Repeated Measures ANOVA tests indicated even though peer-reviewing had no significant effect on the improvement of the scores in their narratives, the influence of tutor conferencing was observed to be significant.