The nursing shortage is a global issue that because there is a growing consensus that identifying flaws and opportunities for improving the working environment in hospital is vital to maintain positive patient outcomes, adequate staffing, high-quality care, nurses’ job satisfaction and hence their retention. The aim of this study was to explore the staffing and resource adequacy in NPE and the association with POs (adverse events). A descriptive correlational study was conducted and participated 395 staff nurses (94.3%) from three university hospitals in Malaysia over two months, from January to February 2011. In this paper, the results showed that 344 (87.1%) staff nurses rated that was unfavorable ( < 2.50) of “staffing and resources adequacy” in their nursing environment. The findings also indicated a significant negative association between “enough time and opportunity to discuss patient care problems with other staff nurses” and “patient falls” (p = 0.017), and medication errors (p = 0.027), and patient complaints (p = 0.021). In conclusion, adequate staffing and resources remain as an essential aspect in the working environment and thus, this study recommended that management would be well advised to deal with this aspect of creation of healthy work environments to worth the effort to maintain positive patient outcomes, adequate staffing and high quality care.