The research question is as follows: To what extent do nurse work environments affect a hospital’s performance? The purpose of this paper is to identify potential relationships between a popular measure of nurse work environments called the Practice Environment Scale of the Nursing Work Index (PES-NWI) and patient outcomes, specifically 30 day mortality. While previous research on the same topic have largely utilized traditional regression approaches to study the relationship, this paper will use a pre-processing technique called matching to reduce the imbalance between observations in the treated and control groups. Matching enables us to reduce biases frequently present in many social science studies and strengthen the validity of the conclusions drawn. The resulting comparison of patient outcome showed no statistically significant difference between high and low PES-NWI hospitals.