After an investigation, the Central Ethical Review Board in Sweden has recommended the retraction of the Report “Environmentally relevant concentrations of microplastic particles influence larval fish ecology,” by Oona M. Lönnstedt and Peter Eklöv, published in Science on 3 June 2016 (1). Science ran an Editorial Expression of Concern regarding the Report on 1 December 2016 (2). The Review Board’s report, dated 21 April 2017, cited the following reasons for their recommendation: (i) lack of ethical approval for the experiments; (ii) absence of original data for the experiments reported in the paper; (iii) widespread lack of clarity concerning how the experiments were conducted. Although the authors have told Science that they disagree with elements of the Board’s report, and although Uppsala University has not yet concluded its own investigation, the weight of evidence is that the paper should now be retracted. In light of the Board’s recommendation and a 28 April 2017 request from the authors to retract the paper, Science is retracting the paper in full.