SUMMARY3‐D karyotype analysis is developing rapidly due to the availability of confocal microscopes and CCD video cameras, and the development of 3‐D processing techniques. Here, image enhancement and visualization techniques specifically designed for 3‐D karyotype analysis are described. To facilitate a good comparison between the different techniques, the same 3‐D image, obtained with a confocal scanning laser microscope (CSLM), of a mitotic prophase nucleus of a root‐tip cell of Crepis capillaris was used throughout. Besides well‐known stereoscopic presentation, another means of improving depth perception is shown, i.e. a solid modelling algorithm, which simulates the process of fluorescence.An interactive routine to dissect objects in the image is presented as an alternative for automated segmentation algorithms, which cannot be applied to closely apposed or merging objects.As an example of a convenient way to reduce the vast amount of data (2 Mbyte per image), a partly automated 3‐D cursor is presented in detail. This cursor is used to trace the central axes of chromosomes and record them as strings of Cartesian coordinates. The advantages of a computer graphics display, which facilitates real‐time rotation and hence is a powerful tool in studying 3‐D features of chromosomes, are also shown.