Introduction: Pain is a common problem after heart surgery and the main purpose of this study was to evaluate the effect of predictability and sense of control over the pain is open heart surgery.For this purpose, the patients were measured variables as well as the administration of pain. Way of taking the traditional group (by nurses) was divided and controlled by the patient.

Method: This descriptive and quasi-experimental research. The sample consisted of 80 patients without diabetes over 60 years (in four categories) who underwent open heart surgery is a surgical procedure and anesthesia were the same and were selected by all of them. The assessment tool visual scale and scale Rotter (internally and externally) to measure and control the source of people's expectations of 29 is binomial.

Results: predictability and self-control method with a significance level (p=0.00) is a significant difference between the pain and the feeling of control with a significance level (p=0.087) no significant difference in pain intensity.

Conclusion: predictability on the amount of morphine and pain-left cardiac surgical patients affected. But the sense of control over the amount of morphine and the pain does not affect cardiac surgical patients. Drug use (nurse or PCA) also affect the amount of morphine and pain-left cardiac surgical patients.