Spread one side of each slice of bread with mayonnaise.
Top 4 slices of bread with a lettuce leaf and 2 slices of chicken; cover each with another slice of bread.
Top each with a lettuce leaf, 2 tomato slices, and 2 slices of bacon, cover each with remaining slices of bread, mayonnaise side down.
Cut each sandwich into 4 triangles. (Insert a wooden pick in each triangle, if necessary.)