The invention relates to a male undergarment brief which through simple construction forms a defined genital pouch and a secured leg opening edge. The brief includes front and rear panels. The front panel comprises two knitted cotton panels having identical shapes which are obversely stitched together thereby forming overlapping fly openings. The two knitted panels provide for a pair of concave lower edges which make up a portion of the leg openings. The concave edges are provided with elastic strips which in their unstretched condition are approximately 2/3 the length of the concave edges. The elastic strips are each stretched to the length of the concave edges and then secured thereto. With the contraction of the elastic strips, a shirring takes place on the panels forming a genital pouch and secure leg openings.