Background: Inconsistent hand hygiene puts people who inject drugs (PWID) at high risk of infectious diseases, in particular skin and soft tissue infections. In healthcare settings, handwashing with alcohol-based hand rubs (ABRH) is recommended before aseptic procedures including intravenous injections. We aimed to evaluate the acceptability, safety and preliminary efficacy of an intervention combining ABHR provision and educational training for PWID. Methods: A mixed-methods design was used including a pre-post quantitative study and a qualitative study. Participants were active PWID recruited in 4 harm reduction programmes of France and followed up for 6 weeks. After baseline assessment, participants received a face-to-face educational intervention. ABHR was then provided throughout the study period. Quantitative data were collected through questionnaires at baseline, and weeks 2 (W2) and 6 (W6) post-intervention. Qualitative data were collected through focus groups with participants who completed the 6-week study. Results: Among the 59 participants included, 48 (81%) and 43 (73%) attended W2 and W6 visits, respectively. ABHR acceptability was high and adoption rates were 50% (W2) and 61% (W6). Only a minority of participants reported adverse skin reactions (ranging from 2 to 6%). Preliminary efficacy of the intervention was shown through increased hand hygiene frequency (multivariable linear mixed model: coef. W2 = 0.58, p = 0.002; coef. W6 = 0.61, p = 0.002) and fewer self-reported injecting-related infections (multivariable logistic mixed model: AOR W6 = 0.23, p = 0.021). Two focus groups were conducted with 10 participants and showed that young PWID and those living in unstable housing benefited most from the intervention. Conclusions: ABHR for hand hygiene prior to injection are acceptable to and safe for PWID, particularly those living in unstable housing. The intervention's educational component was crucial to ensure adoption of safe practices. We also provide preliminary evidence of the intervention's efficacy through increased hand hygiene frequency and a reduced risk of infection.