A transformational nursing professional practice model (PPM) was developed and implemented in the London Health Sciences Centre's renal program. The purpose of this study was to examine the impact of a renal nursing PPM on nurses'perceptions of empowerment, characteristics of practice environments, and nursing outcomes. Quantitative and qualitative methodologies were used in this study. This paper will focus primarily on the quantitative results. The qualitative results are presented in Part II (Harwood, Ridley, Lawrence-Murphy, White, Laschinger, Bevan, & O'Brien, in press). A "then-and-now" design was used. There was a significant (p = .005) improvement post-PPM implementation in the nursing foundations for quality of care subscale of the Nursing Worklife Index-Practice Environment Scale (NWI-PES) and organizational relationships (p = .016) measured by the Conditions of Work Effectiveness II (CWEQ-II) Questionnaires. This study provides evidence for PPMs and primary nursing as effective frameworks to positively impact nursing and patient outcomes in a hemodialysis unit.