Baseball hats can be washed in the machine if the inside of the visor is plastic. Our baseball hats visor is made of plastic so you can throw them in the machine with cold water and washed them. I would not put them in the dryer I would let them air dry. You don't want to put them in the dryer because baseball hats are made of cotton and they will shrink.Make sure you do not put in the washer a baseball hat that has the inside visor made of cardboard. It will ruin the hat when the water reaches the cardboard. In a case where the visor is cardboard you would only spot clean the hat