Over the last 15 years a wealth of linkage maps and quantitative trait loci (QTL) mapping results have become available. The pace of generating this genetic information is accelerating owing to advances in molecular marker technology and the development of software for linkage analysis and QTL mapping. A graphical presentation of this information is often needed, both for publication purposes and for easy and intuitive interpretation. However, the development of tools for the graphical presentation of linkage maps and QTLs has lagged behind. DrawMap (Van Ooijen 1994) was an early program capable of drawing genetic linkage maps. However, the output of this program was not very well suited for use in modern word processors and presentation software. Authors in this field have therefore, of necessity, resorted to the use of general graphics software to compose charts of their linkage and QTL maps. This is always a laborious process, with sometimes disappointing results. Also, each time a map is recalculated when new data become available, this process has to be repeated. For this reason I developed MapChart, a software package that takes as input the linkage and QTL data and generates charts of linkage maps and QTLs. These charts can easily be exported to word processing or presentation software. The charts are exported as vector graphics (Windows enhanced metafiles) rather than bitmaps, which makes them easy to rescale and to edit further if desired.