In this article we describe the mathematics curriculum and teaching practices in a purposive sample of high-poverty elementary schools working with 3 of the most widely disseminated comprehensive school reform programs in the United States. Data from 19,999 instructional logs completed by 509 first-, third-, and fourth-grade teachers in 53 schools showed that the mathematics taught in these schools was conventional despite a focus in the schools on instructional improvement. The typical lesson focused on number concepts and operations, had students working mostly with whole numbers (rather than other rational numbers), and involved direct teaching or review and practice of routine skills. However, there was wide variation in content coverage and teaching practice within and among schools, with variability among teachers in the same school being far greater than variability among teachers across schools. The results provide an initial view of the state of mathematics education in a sample of schools engaged in comprehensive school reform and suggest future lines for research.