This ethnographic study documents how accountability measures skewed the implementation of gender equity reform at one California public middle school serving low-income students of color. In creating single-sex classes throughout the school, the Single Sex Academy (SSA) became the largest public experiment with single-sex schooling in the country, but pressure to raise its standardized test scores diverted the school away from the exploration and implementation of the gender reform. The chronicle of SSA is particularly relevant in light of (a) a recent call to relax Title standards and increase the numbers of public single-sex classes and schools, and (b) the provision of monies mandated by the No Child Left Behind Act of 2001 for single-sex classes and schools, along with the act's imposition of accountability standards and testing.