In classical stitching process, needle holes occur during the penetration of the needle through the fabric. If the waterproofness of the sewn product is important, the water leakage from these holes must be prevented. To prevent this negative situation, different techniques such as sealing of seams with waterproof tapes, joining the textile materials by bonding or welding are used. Among these techniques, there is no needle damage in bonding and welding and all the seam area is covered by thermal or chemical bonding. In sewing technology, the water leakage is prevented by covering all the seam area with seam sealing tape. These three methods have different effects on the physical properties of the seams obtained. Instead of covering the whole seam area, covering just the needle damages is the focus of this research. With this aim, fusible sewing threads were used to cover the needle damages to increase the waterproof performance of seam line. The fusible sewing threads have not been used for obtaining waterproof seams before. In this research, the fusible sewing threads were used as lower thread in different combinations. Initial results of waterproofness test show that, melted fusible threads improve the waterproof performance of seams. In other words, the needle damages on sewn fabric can be covered by melted fusible sewing thread. However, unbalanced seam is the negative side of this research because of using different threads as needle and bobbin thread. Additionally, there is no variety of fusible threads to select an appropriate one for this method. The study is hoped to be a sample for the further studies on this method, using different fusible threads, fabrics, seam types and even improving new fusible threads for this waterproofmg method.