The stitch quality in sewing machines is greatly influenced by parameters associated with needle driving mechanism. The implementation of an optimized needle driving mechanism is of great importance with respect to the effect of needle velocity in the penetration zone, heat generation during stitching and possible damage done on the fabric. Therefore, at first the parameters of the slider-crack mechanism, typically used as the needle driving mechanism, are considered. Then, the required steps to achieve an optimized needle velocity are explained in details. For this purpose, the genetic algorithm technique is utilized. The obtained results confirm that the final needle driving mechanism reaches an optimized needle velocity in the penetration zone.