One of the most pressing problems in the United States is improving student academic performance, especially the nation's burgeoning Latina/o student population. There is a dearth of research on variables associated with student achievement in Latina/o majority schools in urban districts. As the majority of Latina/o students are segregated into central cities and Latina/o achievement issues tend to start in the first three years of school, a study focused on urban elementary schools would help decipher what variables affect Latina/o student achievement during the first few years of school. Considering the continuing challenge of the Latina/o achievement gap, an analysis to understand the relationship between key inputs and Latino/a student achievement is important. The purpose of this research was to better understand the association between financial resources, student demographics, school capacity, and student achievement in majority Latina/o schools. This study breaks new ground by focusing on urban Latina/o majority elementary schools to understand student achievement in relation to inputs. The authors examined trends in student performance while investigating inputs identified in previous studies: teacher quality, school expenditures, and student demographics. They conducted generalized least squares (GLS) regression "change" models (which measure the growth) to understand the relationship between inputs and reading and math achievement in urban elementary schools. The GLS regressions show an influx of White students and bilingual learners have positive and negative associations, respectively, with reading scores. There was no significant association with changes in student populations and math scores. This finding suggests that policy makers and district and school staff should be mindful and proactively develop strategies to address possible shortfalls in reading achievement as student populations change in Latina/o urban schools. (Contains 3 tables.)