This descriptive study was planned in order to assess self-perceived sufficiency levels of nursing students at preparing nursing care plans and also determine the effect of these plans on students' occupational development. Sample of the study was consisted of 55 nursing students who were taking oncological training. Data were collected by using Personal Information Form and Student Care Plan Evaluation Form. Non-parametric tests were used in data analysis. Students perceived themselves 'insufficient' although assessing reproductive neurological and cardiovascular systems, respectively, and also interpreting results of hemogram and urine tests. No significant difference was found between the initial and last nursing care plans prepared by the students during clinical training. Sixty % of students reported that preparing and implementing nursing care plans had favourable effects on their occupational development. Results suggest that students should be well prepared before clinical training programmes and also nursing care plans should be revised and used in more proper and practical ways in order to enhance students' occupational development.