Teacher credibility is a prerequisite of effective instruction. A credible teacher is honest, knowledgeable, and caring. Credible teachers do the right thing when no one is watching; they are in control of the learning environment, but they do this in an enthusiastic and engaging way. Credibility takes time to develop. This study investigated ways in which urban teachers develop and maintain credibility in their classrooms. Participants were 22 secondary mathematics and science teachers in their first year of teaching. The researcher used the B.E.A.R. framework developed by Riner in 2008 to interpret the results. In this framework, B stands for believability; E stands for expertise; A stands for attractive power, and R stands for relationships. Results show that the participants developed credibility by being believable, by possessing content and pedagogical content knowledge, by being in charge of the classroom in a positive way, and by developing relationships with their students.