It is harder to cook a stuffed turkey and there is an increased risk of foodborne illness if the stuffing doesn’t get cooked thoroughly. If you do choose to stuff a turkey, there are measures you can take to help ensure it gets cooked properly.

• Do not put the stuffing in the turkey until just before placing it in the oven. 
  
• Place the stuffing loosely in the cavity and don’t try to overstuff.  Pack the stuffing loose enough to allow the heat to  penetrate the cavity and cook it uniformly with the rest of the turkey.
  
• A stuffed turkey needs to be cooked not only until the turkey itself has reached 165 °F at the three major external check points, but the center of the stuffing needs to reach this temperature as well before the turkey is removed from the oven.
  

For more food safety tips, visit the food safety section of the NSF website.