Introduction: Due to the scarcity at health facilities, personnel, equipments, and progressive increase in health services costs, improving the length of stay (LOS) in hospitals, and factors affecting the LOS becomes much important. Bed occupancy, longer and unnecessary LOS is a waste of resource, and increase if OPP. This study carried out aimed to determine whether there is a relationship between LOS and type of admission, demographic characteristics of patients and physicians.

Methods: This is a descriptive-analytic study. The sample- size includes 350 documents of coronary artery patients undergone bypass surgery in Madani hospital (Tabriz), patients' information gathered by check lists, and physicians related information by direct interview.

Results: There were 70.4% men and 29.6% women 261 patients with elective admissions, whose mean LOS were 5.38 days less than of emergency room admissions. We found a meaningful relation between patients, LOS and type of admission (p<.001). Also there was a meaningful relation between patients LOS and patients situation at the time of discharge (p<.01) .Our findings indicate that there was a reverse relation between number of surgery operations per surgeon and patients' LOS and between patients LOS and surgeon professional work(job) out of hospital (p<.01) . Patients document show that average Los is 15.58 days, this is not compatible with the LOS calculated using time formula: 10.72 days.

Conclusions: What surgeon believes as to be patients LOS is 5 days less than what actually happens. Considering our findings for elderly the LOS should be reduced and thereby home ô°û 9 / ؛یپ°û 52 / پü‎³ 5831 care and community care must be taken in to account. On time diagnosis and hospitalization and as well as contracting with nonacademic surgeons is recommend.