Background: Cotton fever is a febrile syndrome occurring after intravenous drug injection. Although its clinical presentation is well described in the literature, data regarding prevention is lacking. We aimed to assess proportion and correlates of cotton fever experience among people who inject opioids. Methods: We performed a cross-sectional study using data from the community-based survey PrebupIV conducted in France in 2015 among 557 people who regularly injected opioids. Self-reported sociodemographic data, together with data on substance use, injecting practices and occurrence of cotton fever were all collected through face-to-face (n = 398) or online (n = 159) questionnaires. Factors associated with cotton fever experience were assessed using logistic regression model. Results: Over half of the participants (54%) reported cotton fever experience. In the multivariable logistic regression, crack cocaine injection (adjusted Odds Ratio (aOR) = 1.96, 95% Confidence Interval (CI) = 1.03-3.63), longer duration of opioid use (for 1 year of use: aOR = 1.05, 95%CI = 1.02-1.09), and filtering mainly with cotton filters (compared with membrane filters, aOR = 1.86, 95%CI = 1.24-2.78) were all associated with cotton fever experience. Conclusions: Our findings highlight that cotton fever is a frequent complication of injecting drug use. Avoiding the use and reuse of cotton balls to filter injected solutions, and promoting membrane filters use could reduce the risk of the condition occurring.