Alternative assessment has made remarkable changes in SLA instruction. Along with the assessment, Computer Assisted Language Learning (CALL) and technological developments have penetrated into instruction as well. This study was an attempt to compare the effect of wiki and e-portfolio on writing skill of Iranian intermediate EFL learners. To do so, 81 out of 107 participants of 9 intact classes were homogenized by the Preliminary Test of English. They attended a 14 session term in two experimental and one control groups. Following the pretest, the writing points were taught in each group. Meanwhile, the students in both experimental groups were instructed to use technology (wiki and e-portfolio) to write their assignments on specific topics, and also they were requested to assess, to give feedback and comments on their classmates' assignments online and working collaboratively on their feedback in the classes accompanied with the feedback provided by the teacher. Besides, the students in control group were required to do their assignments paper-based and bring them back to the class in order to correct problems. At the end, the posttest of writing was administrated. The results of statistical analysis revealed that applying CALL in both forms of wiki and e-portfolio were significantly more effective in learners' writing than the conventional way. However, wiki could encourage higher levels of progress in writing skill in comparison with using e-portfolio.