Background: People who inject drugs (PWID) are at increased risk for bacterial skin and soft tissue infections (SSTIs). Although SSTIs pose significant health risks, little is known about their prevalence and characteristics in the population of PWID in the United States. This study investigates whether behavioral factors related to skin and equipment hygiene and tissue-damaging injection practices are associated with recent SSTIs among PWID. Methods: Active PWID were recruited using targeted sampling in San Francisco in 2011-2013. Interviewers collected information on behavioral risk factors of past-month self-reported SSTIs. Inferential analyses used multivariate logistic regression methods (i.e., generalized linearmodel) to characterize risk factors for past-month SSTIs. Results: The self-reported prevalence of lifetime, past-year, and past-month SSTI was 70%, 29%, and 11%, respectively. Several factors were significantly associated with past-month SSTIs in bivariate analysis, including injecting nonpowder drugs (odds ratio [OR] = 3.57; 95% confidence interval [CI] = 1.23, 10.35; P = .01), needlelicking before injection (OR = 3.36; 95% CI = 1.28, 8.81; P = .01), injecting with someone else's preused syringe/ needle (OR = 7.97; 95% CI = 2.46, 25.83; P
