Clostridium difficile reactive arthritis is a rare disease; only 5 pediatric cases have been reported in the literature. Its diagnosis is challenging. It manifests as asymmetric aseptic poly- or oligoarthritis, contemporary to infectious colitis, usually after a period of antibiotic therapy. We report a new case in a 7-year-old boy who presented with unusual polyarthritis affecting 12 joints 1 month after antibiotic therapy with amoxicillin-clavulanate. Punctures of both hip joints proved sterile but significantly improved symptoms. Diarrheic stool cultures during hospitalization provided the diagnosis. Antibiotic therapy using metronidazole completely resolved pain and joint swelling within a week. After 1 year of follow-up, there has been no recurrence. We present a review of the literature on this disease and underline the advantages of joint aspiration in this condition with the dual aim of not missing septic arthritis and effectively relieving pain.