Superior mesenteric artery syndrome (SMAS) is a rare and life-threatening disease that affects women more frequently than men. SMAS is characterized by extensive compression of the 3rd part of the duodenum between the aorta and the superior mesenteric artery. This compression results in chronic, intermittent or acute obstruction of the small bowel due mainly to the lack of fat between the aorta and the superior mesenteric artery, which increases the angle between the aorta and superior mesenteric artery and the end of the duodenum, causing intestinal obstruction. The goal of supportive treatment is to increase both body weight and the angle between the mesenteric artery and the abdominal aorta. This case involved a 14-year-old girl with low body weight who suffered from SMAS. Her symptoms included recurrent, severe vomiting and bloating, which necessitated her taking time off from school, causing further anxiety and leading to agitation, resistance to further treatment and care, and more-severe symptoms. During the period of nursing care from August 14th to August 30th, 2017, the author identified symptoms of nutritional imbalance and anxiety. Care initiated to improve nutritional status included: (1) improving nutritional intake, (2) promoting comfort, and (3) maintaining caloric intake. Care initiated to reduce anxiety included: (1) increasing self-control, (2) providing opportunities to participate in treatment planning, and (3) refocusing attention on self-worth. At the end of care, the patient had gained weight, the angle between the upper mesenteric artery and the abdominal aorta had increased, the symptoms had subsided, and anxiety had been alleviated. This nursing experience offers a reference for nurses facing similar cases of clinical care.