Radiation exposure in cath. Lab. is considered one of the highest among X-ray workplaces. This is affected by many factors, including the type and degree of protection by the operating physician and other personnel’s and by the number of cases done. Percutaneous Transluminal Coronary Angioplasty and electrophysiological studies are among the highest in exposure. Exposure as high as 5-sievert has been reported (Leung and Martin, 1996), for practical reasons 1-m sievert is equivalent to 10 chest X-rays (CxR) (Bakalyar et al., 1997). Radiation sources in cath. Lab are obtained either from fluoroscopy or from cine. The first is for guiding catheters, and the second is for recording, exposure is more from the cine though it is used in shorter times. Average exposure from coronary angio is nearly equivalent to 120 CxR and from PTCA is around 200 CxR (Leung and Martin, 1996). Important biological hazards include transient skin erythema and skin ulcers (Fig. 4).1 Radiation exposure causes Deoxyribo Nucleic Acid alteration which is usually repairable but if not may lead to genetic malformations and predispose to malignancies.1 Also it may affect the eyes causing cataracts.2 Figure 4 Non-healing skin ulcer almost one year after radiation exposure in cath. Lab, the patient had coronary stent to his right coronary artery. Pregnancy is special issue in radiation protection for patients and staff. Recommendation for staff is to report pregnancy as soon as possible, to wear full lead aprons, to put dosimeter at waist under lead apron to record the exposure of the fetus, to minimize exposure in general, and to avoid unnecessary exposure. In our center we take the pregnant staff completely out of cath. Lab to some administrative work or to another area where there is no radiation exposure. For pregnant patients cath. Lab procedures should be done only for emergency case. The patient should be protected by lead aprons especially her back. The exposure should be minimized to the least safe amount to do the procedure, fortunately this is uncommon situation. The main radiation hazards in pregnancy are to the fetus because radiation hazards are usually proportional to rate of growth of tissues which is fastest in a rapidly growing fetus. Fetal wastage, intrauterine growth retardation, mental subnormality, teratogenicity and leukemias are among possible hazards to the fetus (www.safety.duke.edu/RadSafety/fdose/fdrisk.asp). The attending cardiologist and the radiation safety officer are both responsible to apply the rules of radiation protection, there are three main rules. (1) Time to minimize the time of exposure by all means, unnecessary personnel should not be inside the lab, do the least number of shots to finish the study, use cine sparingly, and minimize using oblique views which increase the exposure significantly. (2) Distance by stepping away one meter from the source of radiation, a person decreases the amount of exposure to one quarter, so attending staff should stay as far as possible from radiation (Fig. 3) (Beston et al., 1998).3 Figure 3 Using lead aprons or not using it, distance is an effective way of protection from radiation hazards, in the graph above moving 2 ft away from radiation source decreased exposure significantly. (3) Shielding using lead aprons the right way (Fig. 2), using movable shields between the operator and the source of radiation, wearing leaded glasses (Fig. 1) all that can help to minimize exposure and should be a common practice. Figure 1 Leaded glasses is important for eye protection esp. from cataract caused by radiation exposure. Figure 2 Good radiation protection in a pregnant staff, apron > 0.25 mm lead, good overlap, and also neck collar for thyroid protection. Lead aprons should be at least 0.25 mm and should be checked for cracks and should be hanged upright to avoid its damage. There is no clear limit of safe exposure to radiation, so the rule of as low as reasonably achievable should be followed. The maximum allowed exposure limits to 20 m sievert/year averaged over 5 years (Radiation Safety within the Department of Radiology-Ionising Radiation Regulations, 1999). We should remember that exposure to radiation is painless, you cannot see it, cannot feel it and worse than that is that its harmful effect may take months or even years to express it. In conclusion, the most effective rules of protection are wearing lead apron the right way, shielding, distance and time.