Introduction: In a four-year undergraduate level , the nursing students have to get prepared in the patients education, designing care plans, applying nursing processes and exercise the clinical decisions, in addition to learning practical skills. Therefore, multiple clinical teaching strategies in nursing must be applied. In this study the sheets for the mentioned fields were designed and used. Methods: In this action research in Tabriz University of Medical Sciences, 64 nursing senior students and related instructors participated. Clinical written assignment included the patient’s health condition sheet, tables showing the used medicines and the precautions, the clinical and paraclinical tests and the results, identifying the patient problems, designing and implementing care plan and writing nursing reports with SOAPIE method. The instructors’ viewpoints were achieved through the group discussions and their notes taken. The perceived competency of the students was obtained through a questionnaire. The qualitative data was analyzed by the content analysis and quantitative using SPSS. Results: Both the students and the instructors agreed with the clinical written assignment. The desired care competency of the students before and after assignment was statistically significant (p<0.05). According to the instructors, intervention was useful for the senior students who have passed the courses needed for completing and using the different parts of these forms. Conclusion: Since a need is always felt in the trends of the nursing clinical teaching, the researchers recommend the clinical written assignment and their application along with other strategies for senior nursing students in clinical teaching.