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 Ni-60 from the decay of radioactive Fe-60 (half life 1.5 Ma) and of radiogenic Cr-53 from the decay of radioactive Mn-53 (half life 3.7 Ma) in meteoritic minerals. (c) 2006 Elsevier B.V. All rights reserved.