We present the technique, employed in our initial experience using a magnetic device for liver retraction during bariatric procedures, and the results or the comparison of the success rate of adequate exposure and the time required for it, using te magnetic system and the Nathanson's retractor. Fifty patients underwent bariatric procedures using a magnetic device (IMANLAP™) to intend elevate the left lobe of the liver during the procedure, a clamp attached to a 15cm polyethylene tube was placed in the upper left crus, the tube was passed under the left lobe of the liver and holded with another clamp attached to a small magnet, that was captured with a big external magnet attached to a flexible arm over the skin in the epigastrium or the right upper quadrant. In this group 36 procedures were sleeve gastrectomies (17 multiport, 9 single port and 10 reduced ports) and 14 were multiport gastric bypasses. The time employed to satisfactorily obtain adequate exposure with the magnetic system was compared with the time required to place a Nathanson's retractor in fifty multiport bariatric procedures (26 sleeve gastrectomies and 24 gastric bypasses). Student independency test was used to compare the times required for liver retraction in both groups,