Abstract The Cameca NanoSIMS 50 is a new generation ion microprobe, characterized by high spatial resolution (down to 50 nm), high transmission, and simultaneous detection of up to six isotopes. After 4 years of operation the NanoSIMS has now become a well established tool in cosmochemistry which has significantly contributed to a better understanding of the presence of presolar matter in primitive solar system materials and on the early solar system history. Examples of important breakthroughs are: (i) discovery of silicate stardust in interplanetary dust particles and primitive meteorites; (ii) extension of isotopic studies to submicrometer-sized presolar SiC and spinel grains separated from primitive meteorites by chemical and physical treatments; (iii) identification of isotopic heteorogeneities within micrometer-sized presolar grains; (iv) coordinated NanoSIMS-TEM studies made it possible to obtain simultaneous information on the mineralogy, structure, and isotopic composition of presolar materials; (v) detection of radiogenic 60Ni from the decay of radioactive 60Fe (half life 1.5 Ma) and of radiogenic 53Cr from the decay of radioactive 53Mn (half life 3.7 Ma) in meteoritic minerals.