This study investigated students' plagiarism practices in Tanzania higher learning institutions by involving two universities-one public and one private university as a case study. The universities involved have honour code and policies for plagiarism detection however they do not employ software for checking students' plagiarism. The study employed qualitative research approach within the interpretive paradigm. The participants for the case study were purposively selected. Data were collected using focus group discussions and documents analysis (assignments, dissertations and proposal suspected for plagiarism). The findings indicated that plagiarism is a critical problem for the students in sampled universities as assignment submitted during the course of study contains a substantial text that was copied from other sources without acknowledging the original authors. Moreover, study findings also shows that most students had understanding that plagiarism is the academic dishonest, however, this has not stopped them plagiarizing. Factors such as the access of internet, shortage of books, student's laziness and poor academic writing skills played a key role in students' plagiarism at the two universities. Based on these results, the study recommends universities to have adequate resources in particular software for detecting plagiarism. In addition, lecturers/instructors to play their role effectively in educating students about the effects of plagiarism in academic works which to some extent will minimize the problem of direct copying and pasting other peoples' works without acknowledgment.