Introduction: The internship course is a very important part of each university course. The present study aimed at designing and validating a standard instrument for evaluating the internship course in the field of Occupational Health and Safety Engineering (OHSE) from the perspective of trainees. Methods: The dimensions and items of the tool were developed using the panel of experts, syllabus provided by the Iranian Ministry of Health and Medical Education, and literature reviews. Validity of the tool was assessed using face validity, Content Validity Ratio (CVR), Content Validity Index (CVI), and Impact Score (IS). Reliability was evaluated by test–retest reliability analyses and internal consistency (Cronbach’s alpha coefficient). Finally, the internship courses were evaluated during three subsequent years (2016-2018) among 45 students of Shahroud University of Medical Sciences (SHMU) in Iran. Results: The final version of the tool contained five dimensions and 20 items. The CVI and CVR were 0.81 and 0.74, respectively. The ISs of all 20 items were above the minimum acceptable value (1.5). The Cronbach’s alpha coefficient was 0.79 and test-retest Pearson’s correlation coefficient was significant at 0.891 (p<0.001). The overall mean score of evaluation was estimated to be 3.81, which was acceptable. However, poor mean scores were obtained in “access to equipment and laboratory instruments” and “familiarity with job opportunities and internship” dimensions. Conclusions: The results of this study led to a valid tool for evaluating the OHSE internship course. This standard tool can be used to evaluate the perspective of OHSE trainees about the training period and use the results to correct the weaknesses and reinforce the strengths of the training programs.