Resident safety comprises an important topic for nursing practice with up to 33% of residents subjected to an adverse event amongst other safety-related outcomes. In spite of a large evidence base examining the relationship between nurse staffing and resident outcomes, the findings of several systematic reviews remain inconclusive and contradicting. A number of methodological weaknesses in the primary evidence (including cross-sectional study designs, aggregation and non-contemporary measures between exposure and outcome) and lacking causal models guiding analysis of different outcomes diminish meaningful interpretation of the results. The purpose of this review of reviews is thus to provide a comprehensive synthesis of the evidence on the association of direct care nursing home staff and specific resident safety outcomes in nursing homes. We will use descriptive and narrative synthesis to summarize the quantitative results of the relationship between staffing and outcomes. On a purposefully selected subsample of outcomes, we will use a pragmatically-guided narrative approach to extract information from the primary literature regarding explanatory models describing the nature of these relationships. For this analysis we use an inductive qualitative approach following the steps of a logic model to extract information on input, activities, output, outcomes and impact of a stated relationship. This review uses only previously published data and is exempted from an ethical board review. This study aims to advance the research on staffing and resident safety by providing a comprehensive summary and inform future research with regard to causal logic models guiding the analyses.