The frequency of washing bath towels greatly depends on the usage and persons who use it. If it is for kids and babies, it is better to wash and dry them everyday to remain clean and soft and also as you would like to subject them to least risk. Bath towels, if hung properly to dry after each use, can be washed once in three or four days. However, if you have any skin Allergies or dermatological problems, it serves best to wash them daily