In this report from Brazil, evidence of Zika virus transmission from a platelet donor to two patients is presented. To the Editor: Zika virus (ZIKV) is a mosquito-borne virus that has important secondary means of transmission that include perinatal and sexual modes. 1 – 3 The potential for transmission in transfused donated blood components has been a concern owing to the detection of ZIKV viremia in healthy blood donors. 4 This report from Brazil describes two cases of likely ZIKV transmission by blood transfusion from one presymptomatic infected person who donated platelets by apheresis on January 16, 2016. The two leukodepleted platelet units were irradiated with 25 Gy delivered by an IBL-437C gamma irradiator (Cis Bio International) and were transfused in different . . .