There is no authoritative information on how many days of antibiotics should be given to elderly people infected with Stenotrophomonas maltophilia, generally it takes about 14 days to observe the patient’s response to the treatment, adjust the medication regimen appropriately, and combine the medications if necessary, and if the patient’s condition is serious, the time will need to be extended. It is recommended that patients eat a light diet and rest appropriately during the treatment period. There is no specific clinical data on the specific duration of antibiotic use for elderly people infected with Stenotrophomonas maltophilia, and most patients need to use the drug for about 14 days. Most patients need to use antibiotics for about 14 days. However, the specific time of using antibiotics should be based on the patient’s condition. The available medications include antimicrobials such as cotrimoxazole, doxycycline, lomefloxacin, levofloxacin, ciprofloxacin, ticarcillin/clavulanic acid, cefoperazone-sulbactam, and others. If drug sensitivity results are available, then treatment with a sensitive drug is recommended. If there is no significant effect after 72 hours of administration, then consider combining with other drugs; if the patient’s condition is more serious, especially if the underlying constitution is poor, then the duration of medication needs to be prolonged as prescribed by the doctor. Elderly people infected with Stenotrophomonas maltophilia should adjust their diet during treatment, and it is recommended that the diet should be light and nutritious, with less spicy and stimulating food, such as garlic and onion. Patients should ensure adequate rest and should not be overworked. How many days of antibiotics should be used after infection with Stenotrophomonas maltophilia in the elderly can not be generalized, the patient should follow the doctor’s instructions to use the drug, can not stop taking the drug on their own.