BACKGROUND Infections after anterior cruciate ligament reconstruction (ACLR) are rare. No cases of Salmonella infection have been described to our knowledge. CASE SUMMARY We describe a rare case of Salmonella infection in a 23-year-old patient following an ACLR. The patient presented with subacute septic arthritis, 26 d after a hamstring autograft ACLR. The pathogen, Salmonella enterica typhimurium was isolated by bacteriological sampling of the first arthroscopic lavage. Two arthroscopic lavages were required, with intravenous antibiotic therapy for two weeks with cefotaxime and ciprofloxacin, followed by oral antibiotics with amoxicillin and ciprofloxacin for a total duration of three months. This approach treated the infection but two years after the septic arthritis, faced with ongoing knee instability due to graft damage, a revision ACLR with a bone-tendon-bone graft was performed. At the last follow-up, full range of knee motion had been achieved and sports activities resumed. CONCLUSION Infection after ACLR is rare and requires an early diagnosis and management in order to treat the infection and prevent arthritis-related joint cartilage destruction and damage to the graft.