Coronary catheterization is a minimally invasive procedure to access the coronary circulation and blood-filled chambers of the heart using a catheter to recognize occlusion, stenosis, and thrombosis. This procedure is commonly performed through the femoral artery, which may induce possible complications such as bleeding or hematoma. Restricting patient movement was adopted to avoid these complications. The patient has to lie in bed in a supine position for at least 6 hours after angiography. This is an experimental case-control study, conducted to evaluate the effect of early mobilization on back pain. A sample of 300 adult patients was selected by a random sample technique. They were randomly allocated to 100 patients in the experimental group and 200 patients in the control group. The study was conducted from March 2017 to March 2019 at Ahmed Gasim Cardiac Surgery and Renal Transplantation Hospital in Khartoum State, Sudan. The experimental group was mobilized early after 4 hours and the control group had routine bed rest for 6 hours post-sheath removal. Both groups received the usual care. A structured questionnaire and checklist were used to collect data. Data were analyzed by using Statistical Packages for Social Sciences (SPSS).The results revealed that the two groups feel pain varying between no pain and mild (85%) in the cases and in the controls (89.0%) from one hour up to four hours but significant back pain increased clearly at five hours and six hours for the controls group (5th hours severe (6%) very severe (0.5%). P. value 0.000 significant and 6th hours severe (27.5%) very severe (6%). This study concluded that back pain reduction was statistically significant among the experimental group compared to the control group.