Following a request from the European Commission, EFSA assessed the 2017 post‐market environmental monitoring (PMEM) report on the cultivation of Cry1Ab‐expressing maize event MON 810. Like previous years, partial compliance with refuge requirements is reported for Spain. European and Mediterranean corn borer populations collected from North‐eastern Spain during the 2017 maize growing season and tested for Cry1Ab susceptibility show no symptoms of resistance to maize MON 810. No complaints about unexpected field damage caused by corn borers were received through the farmer complaint system. The assessment of farmer questionnaires and relevant scientific publications does not indicate any unanticipated adverse effects on human and animal health or the environment arising from the cultivation of maize MON 810. No information about the use of existing networks involved in environmental monitoring is provided. Overall, EFSA concludes that the evidence reported in the 2017 PMEM report does not invalidate previous EFSA and GMO Panel evaluations on the safety of maize MON 810. As in previous years, EFSA identifies methodological and reporting shortcomings pertaining to resistance monitoring that need revision in future PMEM reports. In particular, the monitoring plan, as implemented in 2017, is not sufficiently sensitive to detect the recommended 3% resistance allele frequency. Consequently, EFSA strongly recommends the consent holder to: (1) achieve full compliance with refuge requirements in areas where maize MON 810 adoption is high (i.e. North‐eastern Spain); (2) increase the sensitivity of the resistance monitoring plan and address previously mentioned methodological, analytical and/or reporting limitations for resistance monitoring and farmer questionnaires; and (3) perform a F2‐screen on European and Mediterranean corn borer populations from North‐eastern Spain. Moreover, relevant stakeholders should implement a methodological framework to enable making best use of existing networks involved in environmental monitoring for the general surveillance of genetically modified plants.