Students' epistemological beliefs are beliefs centred on one's own learning and knowledge. Such beliefs play a major role in the way one approaches problem solving in physics. The intention of this study is to evaluate such beliefs amongst undergraduate physics students. An analytical tool developed by Hammer has been used as a criterion for measuring such beliefs whilst engaged in physics problem solving. A case study of seven students with varying academic abilities and genders were chosen for this study. Each of these students' epistemological beliefs were examined through a clinical interview when they were presented with three different problems to be solved. To achieve a more holistic characterisation of the students' epistemological beliefs, a second person independently, evaluated their beliefs as well. The results reveal that students have personal epistemological beliefs that are different from each other and with respect to each of the problems, they solved.