This scientific opinion evaluates the risk assessment for the authorisation for continued marketing of genetically modified insect resistant cotton MON531 for food and feed produced from it. MON531 was transformed via Agrobacterium. It contains single copies of functional Cry1Ac and NPTII expression cassettes; two fragments of the Cry1Ac cassette and aadA as non-functional elements. Stability of the inserted DNA was confirmed over several generations. Bioinformatic analyses and the levels of recombinant proteins did not reveal safety concerns. Analysis of compositional, phenotypic and agronomic characteristics indicated that MON531 is not different from its conventional counterpart and is compositionally within the range observed among conventional cotton varieties, except for Cry1Ac and NPTII. Safety assessment of Cry1Ac and NPTII proteins and cotton MON531 identified no concerns regarding potential toxicity and allergenicity. Products from MON531 do not contain viable plant parts. The aadA and oriV sequences in MON531 may facilitate the stabilisation of nptII through double homologous recombination in plasmid sequences in the environment. However, considering the expected low frequency of gene transfer from MON531 to bacteria compared to that between bacteria, and the very low exposure to MON531 DNA, the GMO Panel concludes that gene transfer from MON531 to bacteria does not indicate a risk to human or animal health or to the environment in the context of its intended uses. The exposure of potentially sensitive non-target organisms to Cry1Ac protein is likely to be low and of no biological relevance. A PMEM plan is not required. The EFSA GMO Panel considers that information available for cotton MON531 addresses the questions raised by the Member States and that cotton MON531, as described in this application, is as safe as its conventional counterpart and is unlikely to have adverse effects on human and animal health and the environment in the context of its intended uses.