In this research, the author reviewed 70 studies that had examined the relationship between staffing levels and quality in nursing homes ( covering the years 1991 to 2006). The results of the review including all of this literature show that approximately 40% of the quality indicators examined show an association with nursing home staffing levels. Nevertheless, this finding is further interpreted in the context of the limitations of many of these prior studies. The author discusses the limitations of poor quality staffing data, small sample size, quality indicators used, methodological concerns, and underspecified models inherent to many prior studies. The author finds no study representing a "gold standard" exists in this area. Still, the few studies that seem methodologically most robust would seem to indicate that an association between nursing home staffing levels and quality exists. However, the author concludes that studies in this area need to be further enhanced.