BackgroundThe University of California, Irvine Blood Donor Center operates a plateletpheresis donor program utilizing the Amicus Cell Separator. Plateletpheresis donors may donate one or more apheresis platelet (PLT) units per collection event. This study seeks to characterize UC Irvine's donor pool by identifying biometric and demographic attributes predictive of double product (DP) collections.Study Design and MethodsBiometric, demographic and procedural data from 1,786 apheresis donors were collected and entered into Excel spreadsheets. Of the 1,786 successful plateletpheresis procedures performed from January 2009 to April 2012, 1,442 of the donations were performed using double‐needle (DN) kits. Only data from DN‐kit collections were used for statistical analyses. The Classification And Regression Tree (CART) algorithm was used to help identify variables predictive of donating multiple PLT units in a single collection event.ResultsDonors weighing 75.7 kg or greater appear to be twice as likely to donate DPs as those weighing less than 75.7 kg. For donors weighing less than 75.7 kg, females appear to be twice as likely to donate DPs as males. Donors exhibiting platelet counts of 216.5 K/mcL or greater appear to be twice as likely to donate DPs as those with platelet counts fewer than 216.5 K/mcL.ConclusionWeight, sex, and PLT count were identified as the most predictive donor attributes that separate UCI donors into DP donors and non‐DP donors. Greater weights, greater PLT counts, and female sex confer to greater PLT yields per given amount of time. J. Clin. Apheresis 29:139–147, 2014. © 2013 Wiley Periodicals, Inc.