This study aimed at developing writing performance and motivation of EFL students, Az Zulfi College of Education, Majmaah University through using Wikis. The participants were 6^th level English language female students (n= 39). The study adopted the one group pre-post test design. Students were pre-tested using a Writing Performance Test (WPT) and a Writing Motivation Questionnaire (WMQ). The study was an attempt to develop students' collaborative essay writing processes as reflected in their writing performance using wikispaces software. Student' motivation towards writing was also pursued. During the sessions, students were assigned into groups and worked collaboratively on writing their assignments. Students were guided through the writing process to produce well-organized, adequately developed paragraphs and essays. After the treatment, students were post-tested on their writing performance and motivation. Data were dealt statistically using SPSS. Results showed that there was a statistically significant difference in the mean scores of the experimental group students between the pre-and post WPT in favor of the latter. In addition, students' writing motivation was developed.