When a New York school district found a majority of its middle school students scoring below an acceptable level in four major academic areas, it tried many interventions, including a three-year experiment in single-gender classrooms. Although single-gender classrooms are no longer as common in the United States as in years past, recent legislation and feminist research has suggested they may be beneficial to both girls and boys. For the 2004-05 school year, there are at least 147 public schools in the United States offering single-sex educational opportunities (NASSPE 2004). This paper reports findings from the first year of the New York experiment, which showed improvements in student attendance and behavior, but no significant increase in achievement. Interviews with teachers and students provided mostly positive feedback. The authors provide tips for gender differentiation when teaching single-sex classes, but caution that observing the benefits and drawbacks of the single-gender classroom in depth will take more than one year.