Baekgroun: Electrode lead design and materials influence their performance, stability and manipulation characteristics. In our laboratory, we use straight intrzacardiac, active fixation, steroid eluting leads. These features are shared by three brands of pacemarker distributors. Aim: To compare the short term results of three brands of leads used in our laboratory in patients requiring the implant of a pacemarker of cardioverter Material and methods: One hundred and,four patients (mean age 70 years, 59 males) subjected to a pacemarker or cardioverter implant were studied and followed during the first three months post implant. In these patients, 49 Guidant Flextend (R) 4087 or 4088, 27 Saint Jude Tendril (R) 1488T and 10 Medtronic Capsurefix (R) 5076 leads were implanted in the right atrium and 60 Guidant Flextend (R) 4087 or 4088, 29 Saint Jude Tendril 1488T and 19 Medtronic Capsurefix (R) 5076 leads were implanted in the right ventricle. Results: Implant parameters were adequate for all leads. A sub-acute rise in ventricular stimulation threshold was detected in one Flextrend (R) lead. Three atrial leads (two Flextend (R) and one Capsurefix (R)) and one Capsurefix ventricular lead experienced an acme displacement. One patient with. a Flextend lead, had a cardiac tamponade caused by an atrial perforation. Conclusions: The three brands of leads tested can be successfully implanted with comparable parameters and without differences in the evolution of patients during the first three months (Rev Mid Chile 2006 134: 1427-35).