Although toxic shock syndrome (TSS) is rare, multiorgan failure can occur without early identification and appropriate therapy. In particular, a few cases of postpartum TSS due to methicillin-resistant Staphylococcus aureus (MRSA) have been reported. Here, we describe a rare case in which a 32-year-old Japanese woman had TSS due to MRSA that was caused by a perineal infection after a normal vaginal delivery. Twelve days after giving birth to a healthy child, she was readmitted to our hospital due to a 2-day fever and perineal pain without uterine tenderness. She developed emesis and watery diarrhea on the night of admission. On the second day, a diffuse cutaneous macular rash appeared over her trunk. Laboratory data revealed deteriorated renal function and thrombocytopenia. Her history and clinical results were compatible with a typical course of TSS. Administration of ceftriaxone and clindamycin was started immediately after admission and was effective. The patient recuperated steadily over the next week with desquamation of the skin. MRSA was isolated from her vaginal discharge and was found to produce TSS toxin 1 (TSST-1). Furthermore, since MRSA was not detected in the nasal and vaginal cavity during pregnancy, it suggests that vaginal colonization can also occur postpartum and be the disease source in mothers. Therefore, MRSA infections should be considered when treating for postpartum TSS.