We continuously measured the aerosol number size distribution in the particle diameter range between 18 nm and 830 nm with 64 bins per decade resolution by means of a Scanning Mobility Particle Sizer (SMPS, TSI, i.e. a Series 3080 Electrostatic Classifier equipped with a Differential Mobility Analyzer DMA 3081 and a CPC 3776). The measurements were conducted at the Air Chemistry Observatory (SPUSO) at Neumayer III Station (Antarctica) between 1 January 2025 and 31 December 2025. The data are based on an original 10-minute temporal resolution, submitted as 60-minute averages. Aerosol number size distribution measurements are part of the air chemistry long-term observations at Neumayer III. Details about the instrument can be found under resources of the corresponding metadata link: https://hdl.handle.net/10013/sensor.81ece554-068a-4c6e-8de5-1ef1944c0156