The main objective of the study was to examine the effects of Web-based academic projects on EFL students’ writing performance, critical thinking skills and their motivation towards writing. A single group quasi-experimental design was employed, involving 35 second year English major students (30 males and 5 females) enrolled in advanced English course at Woldia University. Comprehensive sampling technique was used to select participants. Test was used to collect data about learners’ writing performance and their critical thinking skills in writing before and after intervention. Questionnaire was used to collect data about learners’ writing motivation before and after intervention. Textual analysis, students’ diary analysis and focus group discussion were also employed as data gathering instruments in order to triangulate the data obtained through test and questionnaire. The data obtained through students’ tests were analyzed quantitatively using one-way repeated measures Multivariate Analysis of Variance (MANOVA), as well as the data obtained through students’ questionnaires were analyzed using paired sample t-test. On the other hand, the data gathered using textual analysis, focus group discussion and students’ diary analysis were analyzed qualitatively through thematic analysis. Specifically, Google Docs was employed in this study among other academic Web-based writing applications. Hence, the results obtained from the MANOVA test indicated a significant difference in learners’ writing performance and critical thinking skills before and after the intervention which, F (10, 11) =9.013b P= .01 Wilks’ Lambda = .217, ηp2=.783, observed power =1.000. Similarly, the result obtained through using the paired sample t-test showed significance difference between learners’ writing motivation before and after intervention, particularly the highest mean difference was found in self-efficacy dimension in which its MD=-0.474 (t =- 7.794, p<.05). Likewise, the findings obtained through using the thematic analysis strengthen the statistical findings. Overall, the results of the study suggest that collaborative writing using academic web-based projects specifically, via Google Docs positively influenced students’ writing performance, critical thinking skills, and their motivation towards writing. Therefore, EFL teachers can employ academic Web-based projects besides the face-to-face collaborative writing approach as a means to develop their students’ writing performance and critical thinking skills, and increase their students’ motivation towards writing through considering the necessary conditions in using it in to account.