Environmental degradation is a major global health threat, and the healthcare sector functions as both its victim and perpetrator. To effectively inform mitigation strategies it is essential to quantify the environmental burden originating from healthcare activities and then favour environmentally preferable treatment options. This Switzerland-based study evaluated and compared the environmental impacts from surgical and conservative care pathways after an anterior cruciate ligament injury using Life Cycle Assessment; it also identified the environmental hotspots stemming from the surgery itself, as well as from physiotherapy. Environmental impacts were quantified across 18 ReCiPe midpoint impact categories. Results indicated that, on average, after an anterior cruciate ligament injury, the surgical pathway imposes at least an 8.5-fold greater relative environmental burden than the conservative pathway. Regarding the anterior cruciate ligament surgery alone, the hotspots of environmental impacts were identified as the manufacturing of single-use products, transportation of patient and staff, and the use of heating-ventilation-air-conditioning and electricity. Regarding physiotherapy, results indicated that a large share of environmental impacts can be attributed to transportation of patient and staff, laundry, and space heating. This difference in environmental impacts emphasises the importance of a careful patient allocation between these two care pathways. Recommendations to reduce the environmental impacts from surgery should prioritise investing in reusable equipment, streamlining surgical instrument trays, and opting for occupancy-based heating- ventilation-air-conditioning. To reduce the environmental impacts originating from physiotherapy, recommendations should encourage soft mobility, patient’s self-management, and the physiotherapist’s following of evidence-based guidelines. Reducing laundry frequency can be relevant as well.