Evaluating clinical performance of nursing students as a resource to determine educational needs and decision-making is essential to change the educational environment and improve the quality of education. The aim of this study was to evaluate the professional behavior of nursing students in the clinical environment with the Small Scale Professional Assessment Tool (P-MEX). This descriptive cross-sectional study was conducted with the participation of 86 nursing interns of Ahvaz University of Medical Sciences in 2019. Data collection tools were demographic information questionnaire and P-MEX Cruess evaluation form. The validity and reliability of this instrument was evaluated by observers and was determined with Cronbach's alpha coefficient of 76%. Data were analyzed using SPSS software version 20 and descriptive statistics, independent t-test, analysis of variance, and post hoc test. In professional skills, most participants in the first stage were 51.2% at the average and expected level and 48.8% above the expected level, and in the second stage, most were 84.9% at the average and expected level and 15.1% higher than they were as expected. In this study, based on the evaluation scores in two stages, although the average total clinical skills scores of most students were within the expected range of the 4-point Likert scale, the skill scores were lower in the special wards. Therefore, for the full development of professional skills, it is necessary to develop appropriate methods of planning and training in the field of professional behaviors.
