To assess the effect of changing position and early ambulation on the urinary retention, back pain, bleeding and hematoma after cardiac catheterization. Methods: This is a quasi-experimental study, including four groups of 35 patients (140 samples with random sampling). group A received a common protocol, remaining supine and flat in bed for 6 hours. Patients in group B were positioned after Angiography as the first time sleeping in the back and the head of the bed was raised to an angle of 15 degree; in the second hour head of the bed was changed to 30 and in the third hour to 45; then position was changed to the right side for half an hour and to the left side for another half an hour, and in the sixth hour the patient was allowed to get out of the bed. In group C, patients had early ambulation in the fourth hour after angiography. In Group D, combination of changed position and early ambulation were used. Then the amount of bleeding, hematoma, back pain and urinary retention were measured in 0, 1, 2, 4, 6 and 24 hours after angiography. Data were collected by the use of personal information questionnaire and Numeric Pain Intensity Scale and Christenson check list for investigating the amount of bleeding and hematoma.