Toxic reactions can appear after pressurised flushing of soft tissue with octenidine (OCT) containing disinfectants. Their use for surgical disinfection could complicate the diagnosis of possible contamination. In patients with open lacerations of their hand's subcutaneous tissue samples were taken before and after surgical disinfection with Octenisept® and analysed by ultra‐high‐performance liquid chromatography coupled to tandem mass spectrometry (LC–MS/MS). In 16 out of 20 tissue samples, OCT was detected after disinfection (lower limit of quantification (LLOQ)=10 pg/mL/mg). The concentration of OCT was below the LLOQ, estimation of mean of 0.6 pg/mL/mg (0.22–0.98 pg/mL/mg, 95%‐CI) before disinfection and mean of 179.4 pg/mL/mg (13.35–432.0 pg/mL/mg, 95%‐CI) after disinfection. This study shows that the disinfection of open wounds with Octenisept® leads to a quantifiable concentration of OCT in open wounds. In cases of suspected OCT‐mediated toxic reaction, the use of antiseptics containing OCT should be avoided.