What really matters in supporting the development of effective urban teachers? This text seeks to respond to this question by reporting on a study of the professional growth of twelve high school teachers identified as effective by both administrators and students at their school sites. Teachers who participated in the study varied significantly in surface level characteristics, including years of experience, academic preparation, and personal background. However, extensive interviews revealed that participants shared important similarities in their professional growth experiences. In particular, all participating teachers identified opportunities to develop meaningful relationships with students and opportunities to critically reflect on practice as having had significant impact on their professional growth. The common professional growth experiences of these teachers may indicate directions that could be helpful in supporting the professional growth of all urban high school teachers.