s u m m a r y Background: Psoas muscle abscess is a previously rare disease that has increased in its reported prevalence because of improved diagnostic tools. The literature on psoas muscle abscess mostly consists of case reports and case series. Methods: We analyzed medical records, such as characteristics, pathogens, and disease pattern, from our hospital in the past 8 years and report nine cases of psoas abscess. We also reviewed the literature for case series and performed a meta-analysis to assess the current characteristics of this disease since 1986. Results: We reviewed a total of 36 studies, with a total of 682 cases. The average age was 52.6 years, and the mortality rate was 8% (55 of 682). In 35 studies, a total of 274 cases (40.77%) received drainage (274 of 672), whereas 290 (43.15%) received surgery. In 522 cases, the ratio of primary to secondary etiologies was 1:1.71. In 209 cases, Staphylococcus aureus, and in 70 cases, Escherichia coli were identified as the pathogens from culture data. Compared with Ricci's case series, we found an obvious increase in prevalence of secondary causes (63.2% compared with 21.8%) and higher mortality in recent study (6.7% in Ricci's study and 8.1% in recent study). There was an obvious shift toward drainage as the treatment of choice. Conclusions: We conclude that a higher mortality has occurred in recent study, and psoas abscess is an infrequent and easily overlooked infectious disease requiring early diagnosis with favorable results with percutaneous drainage.