In this study, the influence of group work on English as a Foreign language as learners' writing performance at Lam Dong Minority Boarding School was investigated, as well as the students' attitudes about group work. The study included 61 students from Lam Dong Minority Boarding School in Grade 11, who were separated into two groups: one experimental group and one control group. A quasi-experiment was conducted in four weeks to solve Research Question 1. To begin, both the control and experimental groups were given a standardized pre-test, with the findings assessed. A standardized post test was done once the data was analyzed. An independent sample t-test and a paired sample t-test were performed to evaluate if there were any significant differences in writing performance. A questionnaire and an interview in semi structured format with members of the experimental group were performed to answer Research Question 2. To find out if there was any relationship between the scores of writing performance post-test and identified cooperative learning attitudes of the experimental group, the Pearson correlation coefficient was used to measure the strength of a linear association between two variables to answer the Research question 3. The study's findings revealed that group work aided students in the experimental group in making progress in terms of English writing abilities, they outscored students in the traditional learning group. Furthermore, the findings demonstrated that the experimental group's students had an optimistic attitude regarding group work in English as a Foreign Language writing classes. The study also indicated that there was a very small positive association between the experimental group's writing performance post-test scores and their attitude survey score.