The STESYS2 software is a new version of the IBM PC software supporting interactive stereological measurements. In comparison with the previous STESYS, it is enhanced by a number of useful options, e.g. on-line image input via a TV camera coupled with a microscope operating under MS Windows OS. The main advantage, when compared with other such software packages, is the design of the STESYS2 as a module of the freeware image processing system Image Tool which provides a user-friendly environment including a number of image processing and preprocessing routines. Capabilities of the STESYS2 are illustrated by a practical example: estimation of the surface area of capillaries in the terminal villi of human placenta by the Sandau spatial grid method., Z. Tomori, L. Matis, P. Karen, L. Kubínová, I. Krekule., and Obsahuje bibliografii