The fruit fly Rhagoletis zoqui is endemic in temperate climatic regions in Mexico and so far, it did not occur in Germany and the EU. R. zoqui is listed in the Annexes of Directive 2000/29/EC as non-European Tephritidae but it is not listed by name. The species is not listed by EPPO. Rhagoletis zoqui infests the fruits of walnut trees (Juglans spp.). Due to appropriate climate conditions, it is assumed that R. zoqui is capable to establish outdoors in Germany. The establishment in other EU Member States with temperate climate and adequate low winter temperatures is possible, too. Due to its medium damage potential for the production of walnuts, R. zoqui poses a low phytosanitary risk for Germany and a medium phytosanitary risk for other EU Member States. Based on this risk analysis, it is assumed that the pest may establish in Germany or another Member State and cause not insignificant damage. Additionally, R. zoqui is a non-European Tephritidae and therefore a quarantine pest according to Directive 2000/29/EC. Thus, measures should be met according to § 4a of the Plant Inspection Order in order to prevent the introduction. The occurrence of R. zoqui has to be notified. It is recommended to conduct a regional monitoring in locations with Juglans sp. in the near of the trap catch, in order to detect the infestation site and the extent and to control it.