hemming leather pants is very similar to hemming jeans or other heavier-weight materials. For the hem on leather pants to be perfect, it will be critical that the right needle is used and the placement of the hem planned out exactly before beginning to hem the leather pants. Leather, unlike other softer and more-flexible fabrics, will show any misplaced needle strokes, so care must be made to create the right seam the first time.
Determine the desired hem length. The best method is to put the leather pants on with the shoes that you will wear them with. Then, fold the leather at the place of the desired hem and mark with chalk or marker at the fold on the inside of the pant leg.
Cut off excess material, leaving 1 to 1-1/2 inches for the hem. Press the hem in place by folding the material on the line, placing a towel or piece of fabric over the leather pant leg, and pressing with an iron on a dry-heat setting. Leather will show pin marks, so either press a good crease or apply fusible web to hold the hem in place for sewing.
Finish the end of the leather pant leg if desired. This can be done using a straight stitch, zigzag, or a serger, and can also be sewn by hand. Some leather can be left cut and unfinished—it will not fray or split like other materials.
Sew the desired hemming stitch into the leather pants, either by hand or using a sewing machine. Use the appropriate-weight thread, needle, and foot on a sewing machine to handle leather, or heavyweight material and thread. A basic straight stitch or zig-zag stitch can be used on a sewing machine. A straight stitch, back stitch, or other permanent hemming stitch can be sewn by hand.
Iron the completed hem. Remember to place a piece of fabric or towel in between the iron and the leather pants to protect the leather.