In monitoring trials investigating the occurrence and spread of herbicide resistance in German and Swiss Lolium populations 26 samples could be included since 2008. Biotypes which showed resistance to postemergence herbicides were included into a detailed greenhouse trial in 2014. Based on dose-response experiments, resistance factors and cross resistance patterns for cycloxydim, flufenacet, glyphosate, iodosulfuron, meso- and iodosulfuron, pinoxaden and pyroxsulam could be determined. Resistance to ALS as well as ACCase inhibitors was found. In a few cases also resistance to flufenacet could be detected. In contrast, no resistance to glyphosate was discovered. Resistant populations were found in four German federal states (Hessen, Mecklenburg-Vorpommern, Sachsen and Schleswig-Holstein). Two populations were resistant to all cereal selective post-emergence herbicides and to flufenacet. Some populations from Switzerland indicated presence of ACCase inhibitor resistance. In the future, more problems with herbicide resistant Lolium species as weeds in cereals may arise due to limited amount of available selective herbicides and climatic change with more favourable conditions for Lolium spp. as weeds.