Background: Advanced practice nursing and midwifery education was introduced globally and in Kenya with an objective of introducing high quality nursing and midwifery care services that would result to improved patients outcomes. Currently there are hundreds of advanced practice nurses and midwives who are underutilized and more precisely in Kenya due to little available evidence of the impact of advanced practice nurses and midwives on patients' outcomes. Objective: To review available evidence on the impact of advanced practice nurses and midwives on patients' outcomes. Methods: A wide search method was used to site literature from variety of databases. Review process involved inclusion of qualitative, quantitative and mixed method research studies that were recent and relevant to this study's objective. Data were abstracted, organized into themes and sub-themes, summarized and results were reported by means of narrative synthesis. Quality of the research study was evaluated by using Mixed Method Appraisal Tool (MMAT) version 2018. Measures of advanced practice nurses' and midwives' impact were matched against a set framework including clinical significance for evaluating patient's outcomes. Results: Out of the 10 studies that were included, the results suggested that there was a great impact of advanced practice nurses and midwives on positive patients' outcomes. The outcomes were; early detection of disease complications, efficient and effective continuity of care, diagnostic accuracy and reduced polypharmacy, reduced length of hospital stay, reduced mortality rates, innovative service delivery, patient safety and satisfaction. Conclusion: There is need for more involvement of advanced practice nurses and midwives in healthcare delivery systems and specifically in Kenya in order to achieve positive patients' outcomes