Objective: This descriptive and retrospective study was conducted to investigate how 2nd grade students in a nursing faculty diagnosed impaired comfort in patients under their supervision using the North American Nurses Association (NANDA) diagnoses based on Gordon's Functional Health Patterns (FHP) Model, and to determine the appropriate treatment approach. Materials and Methods: Seventy-four students who put their theoretical knowledge into practice in the gastroenterology clinic between March 2015 and June 2017 comprised the population and sample of the study. The study data were obtained by examining the care plans of the 74 2nd-grade students of a nursing faculty which were included in their internship files. The review of the 418 nursing diagnoses revealed that 39 of these diagnoses were related to the impaired comfort. The nursing care plans used by the students in providing healthcare to patients included Gordon's FHP and physical examination findings. The nursing diagnoses made by the students were evaluated according to the PES (Problem, Etiology, Symptom) criteria using the NANDA Taxonomy II which included 156 nursing diagnoses list based on Gordon's FHP. The data were analyzed on the computer using numbers and percentages. Results and Conclusion: Although it was possible to diagnose 74 patients (each student was responsible for one patient) with impaired comfort, only 52.7% of them (n=39) were diagnosed with impaired comfort. The evaluation of how to treat people diagnosed with impaired comfort showed that while 15.3% (n=6) of the students' approaches were wrong, 84.7% (33) of them displayed correct approaches. The analysis of the reasons why the students diagnosed the patients with impaired comfort demonstrated that of the causes, 15.6% were related to deterioration in sleep hygiene, 10.3% to stress, 20.6% to staying in the hospital environment, 33.3% to pain / nausea, 7.6% to itching and 12.8% to fatigue. The number of impaired comfort nursing diagnoses made by the students included in the research was 5.6 per student. In the study, although it was possible to diagnose all the patients (n=74) with impaired comfort, only 52.7% of these patients were diagnosed with impaired comfort. It was also determined that 84.7% of the students displayed correct approaches to the treatment of the patients.