This article shows how City-As-School, a progressive public school in New York City, used descriptive inquiry to deepen shared decision making, which is a central value of the school and part of a democratic way of life. Descriptive inquiry is a democratic knowledge-making process that was developed at the Prospect School in North Bennington, Vermont. Guided by a group of teacher leaders, the faculty of City-As-School began to use descriptive inquiry in the 2016-17 school year. Faculty members met regularly in study groups during Friday morning faculty meetings and examined student work using descriptive processes. The teacher leaders planned and led the study groups in collaboration with the school leadership and with the support of an experienced practitioner of descriptive inquiry. This article shows that using descriptive inquiry moved the faculty toward more careful listening to colleagues' differing points of view, giving all voices a chance to be heard and making students and their differences more visible. It also shows that using descriptive inquiry helped the staff of the school navigate a course between unilateral decision making by the school leadership and teacher-driven decision making that did not clearly build toward a vision for the whole. In these ways, descriptive inquiry deepened democracy and shared decision making in the school. The authors of this article are two leaders of the school and the experienced practitioner of descriptive inquiry who supported the inquiry work.