Proper use of source material in second language writing is an essential skill in the academic writing process. The present study investigates source use and plagiarism level in the essay writing process by the English as a foreign language (EFL) student in one of the international universities in Tashkent, Uzbekistan. Thirteen first-year students who failed and then retook the language program were chosen for the purpose of the study. A mixed-methods research design was used to collect the data (i.e., language programs over two subsequent academic years were analyzed for their relevance to the process-based writing). To evaluate the students' opinions on both programs and correct academic citation, a paper-based questionnaire was circulated. The data analysis revealed a positive influence of program two on organizing ideas, incorporating source-text ideas, and using more academic and error- free sentences. A comparative analysis of the plagiarism level and writing performance in students' papers in both programs was performed using the Wilcoxon signed-rank test, which showed a positive difference in the overall writing scores but an insignificant difference in the level of plagiarism. F indings of the study identified that the engagement of the EFL undergraduate students in process-based writing made a positive impact on writing from sources and overall performance.
