This study aimed at investigating students’ views on plagiarism in English academic writing and the factors that plagiarism is usually committed. A descriptive quantitative method was used to describe and explain the phenomenon of students’ plagiaristic behavior. Questionnaire was used as the instrument to obtain the data. The data were collected from three classes of semester six university students at Universitas Islam Negeri (Islamic State University) Ar-Raniry Banda Aceh. The data demonstrated that students perceive some types of plagiarism are more serious than others, ranging from using another author’s whole document, another author’s sentences/paragraphs, another author’s phrases and another author’s ideas. Furthermore, students perceive; 1) copying statements (from websites, electronic journals, and without inverted comas, 2) combining and changing various statements, 3) buying assignments from senior students, 4) using the work of other and using research findings from electronic journals, and 5) copying a friend’s assignment without proper reference as plagiarism act while copying statements from websites and from electronic journals, translating and constructing own sentences into another language from the internet and acknowledging original author are perceived as non-plagiarism acts. The result also indicated that students perceived efficiency gain, lack of understanding, temptation and opportunity, time management and lack of deterrence as the five major factors of why plagiarism is committed. Finally, students’ opinion on the factors of why plagiarism is committed related to many factors such as students’ past experience, today’s problem, or other factors.