The study of academic plagiarism among university students is at an embryonic stage in Spain and in the other Spanish-speaking countries. This article reports the results of a research, carried out in a medium-sized Spanish university, based on a double method approach-quantitative and qualitative-concerning the factors associated with academic plagiarism from the students' perspective. The main explanatory factors of the phenomenon, according to the results obtained, are: a) aspects and behaviour of students (bad time management, personal shortcomings when preparing assignments, the elevated number of assignments to be handed in, etc.); b) the opportunities conferred by information and communication technologies to locate, copy and paste information; and, finally, c) aspects related to professors-lecturers and/or the characteristics of the subject-course (lecturers who show no interest in their work, eminently theoretical subjects and assignments, etc.).