These comfortable boxer shorts are formed from a knitted main tube (1) comprising a front part (5) and a back part, the lower portions of which end in a first and second bottom line (10, 11, 16, 11′, 10; 13, 12) consisting of two front incisions and one rear incision. The first bottom line (10) (10, 11, 16, 11′, 10′) is composed of an edge (16) of a front flap (14) and of two bottom line side ends (10, 11; 11′, 10′) that rise higher than the edge (16) of the flap (14). Said edge (16) of the front flap (14) is sown to the middle of the second bottom line (13, 12), at the rear of the boxer shorts, and two separate crotch parts (15, 15′) (15) are sown between the ends (10, 11; 11′, 10′) of the first bottom line and the ends of the second bottom line (13, 12).