© 2018 John Wiley & Sons, Ltd. This study employs bootstrap data envelopment analysis to measure the technical efficiencies of 48 Kuwaiti retail cooperative societies (coops) during the years 2012–2015. Average profit efficiency falls substantially from 84% to 70% after applying a bootstrap correction. The bias is larger for coops originally identified as being on the efficient frontier. The average coop is too small, but both profitability and efficiency are negatively related to the number of direct branches (mini-marts). Also, coops can increase profitability through greater equity capitalization, whereas better control of labor costs leads to higher profit efficiency.