ABSTRACT Infections after joint arthroplasties represent a devastating and progressively escalating complication with increased morbidity and mortality. The eradication of biofilms from infected implants is still an unsolved challenge. The erbium‐doped yttrium aluminum garnet (Er:YAG) laser, which delivers high‐energy light for rapid tissue ablation, may offer an advancement. This study aimed to evaluate the effectiveness of this laser in removing biofilms from infected implant surfaces. In this prospective study, 31 patients with 33 early postoperative or acute hematogenous periprosthetic joint infections (PJIs) were treated with our modified procedure of debridement, antibiotics, laser irradiation and implant retention (DALIR). Biofilm removal was compared between mechanical cleansing alone and the additional use of Er:YAG laser light. Therefore, swab cultures from the implants were taken at three distinct occasions: post‐arthrotomy, after mechanical cleansing with a fluid disinfectant (LavaSurge), and after additional Er:YAG laser irradiation. The success rate of the DALIR procedure was compared with a prior group ( n = 34) that underwent DAIR procedures without the Er:YAG laser at our clinic. The implementation of the laser system in our DAIR procedure was uncomplicated. The additional Er:YAG laser therapy significantly reduced viable microorganisms on implant surfaces (9.1%) compared to mechanical cleaning alone (42.4%; p < 0.01). The healing rate in our cohort was 78.1%, a substantial improvement over the previous rate of 44.1% ( p < 0.01). Therefore, we recommend the use of Er:YAG laser irradiation as an additional tool for surface disinfection of metal implants in PJIs whenever a DAIR procedure seems to be beneficial. Trial Registration: ClinicalTrials.gov identifier: NCT06440564. Level of Evidence 2B.