The Satellite Application Facility on Climate Monitoring (CM SAF) is a ground segment of the European Organization for the Exploitation of Meteorological Satellites (EUMETSAT) and one of EUMETSATs Satellite Application Facilities. The CM SAF contributes to the sustainable observing of the climate system by providing Essential Climate Variables related to the energy and water cycle of the atmosphere (www.cmsaf.eu). It is a joint cooperation of seven National Meteorological and Hydrological Services, including the Deutscher Wetterdienst (DWD). The cmsaf R-package provides a small collection of R-functions, which are inspired by the Climate Data Operators (cdo). This gives the opportunity to analyse and manipulate CM SAF data without the need of installing cdo. The cmsaf R-package is tested for CM SAF netcdf data, which are structured in three-dimensional arrays (longitude, latitude, time) on a rectangular grid. Layered CM SAF data have to be converted with the provided 'levbox_mergetime' function. The cmsaf R-package functions have only minor checks for deviations from the recommended data structure, and give only few specific error messages. Thus, there is no warranty of accurate results. A Windows binary file and scripts for an easy application of the functions are provided at the CM SAF homepage (http://www.cmsaf.eu/EN/Products/Tools/Tools_node.html).