This systematic review examines the relationship between nurse staffing levels and patient safety and healthcare outcomes. Nurse staffing is a critical indicator of healthcare quality, as inadequate staffing increases workload, delays care, and contributes to missed nursing care. The review aims to synthesize current evidence on how nurse-to-patient ratios, registered nurse hours per patient day, and skill mix influence outcomes such as mortality, hospital-acquired infections, medication errors, falls, pressure injuries, length of stay, readmission, and patient satisfaction. A systematic search should be conducted in databases such as PubMed, CINAHL, Scopus, Web of Science, and Google Scholar using keywords related to nurse staffing, patient safety, healthcare outcomes, and hospital care. Eligible studies may include systematic reviews, cohort studies, cross-sectional studies, and observational studies published in the last 10 years. The expected findings are that higher registered nurse staffing levels are associated with reduced adverse events, lower mortality, fewer complications, better patient experience, and improved care quality. The review highlights the need for evidence-based staffing policies, workforce planning, and leadership support to ensure safe and effective nursing care.