Abstract: This paper reported a case of 77-year-old male patient who developed generalized erythematous macules, bullae and erosion, accompanied by genital mucosa involvement five days after taking compound sulfamethoxazole tablets. Based on patient′s clinical manifestations and auxiliary examination results, the diagnosis of generalized bullous fixed drug eruption was confirmed. Clinicians should be vigilant about generalized bullous fixed drug eruption with genital mucosa involvement and strive for early detection, diagnosis, and treatment.