Preheat the oven to 350 degrees F (175 degrees C).

Cut bacon slices into thirds. Cut large water chestnuts in half. Wrap each water chestnut with bacon; secure with a toothpick. Place on a 9x13-inch baking pan.

Stir ketchup, brown sugar, and Worcestershire sauce together in a saucepan over medium heat until almost boiling; pour over bacon-wrapped water chestnuts.

Bake in the preheated oven until bacon is cooked and crisp, about 45 to 50 minutes.