Background Patients who undertake cardiac surgery usually manifest discomforts. Comfort care plays an important role in the postoperative management of a cardiac surgery patient. Methods A self-made General Comfort Scale was used to evaluate the discomfort factors of 156 adult patients who underwent cardiac surgery in our department of Guangdong General Hospital from January to April 2014. All patients had open chest cardiac surgery under general anesthesia and cardiopulmonary bypass. The reasons for the discomfort were collected and the appropriate comfort cares were implemented. Results Our data showed that the main factors influencing the comfort of surgical patients included pain, thirst, hunger, nausea, vomit, abdominal distension, sleeping disorder,postural discomfort, surrounding and psychological causes etc. Among the 156 adult patients, 153 patients complained of thirst, 141 patients felt painful, 96 patients felt hungry, and 67 patients had sleeping disorders. These discomfort factors affected the treatment and rehabilitation of patients. Conclusions Basic and specific comfort and appropriate nursing cares should be carried out to alleviate the discomfort factors such as sleep disorder, pain and endotracheal intubation, which could protect patients’ benefit and promote their rehabilitation.