A preliminary genome scan for plasma cholesterol levels in pigs was carried out. An experimental population of 370 males distributed in five half-sib families was generated from a commercial Duroc line. These animals were measured for plasma cholesterol, low density lipoproteins, high density lipoproteins and triglyceride concentrations, at 40 (369 records) and 180 (267 records) days of age. All individuals recorded plus the five parental boars were genotyped for 110 informative microsatellites covering the whole genome. The QTL analyses revealed several genomic regions with significant gene effects on plasma cholesterol, lipoproteins and triglyceride concentrations on chromosomes 3, 4, 5, 6, 8 and 12. These results yield very valuable information aimed to understand the genetic architecture of these traits.