An advantage of end-to-side anastomosis is that thrombogenesis in the anastomotic part is less likely than with end-to-end anastomosis. Conversely, the operative procedure for end-to-side anastomosis is more complicated than that of end-to-end anastomosis. We usually perform a modified back-wall technique in which the outflow vessel is dropped over the inflow vessel. We performed end-to-side anastomoses using the single-knot, back-wall, and drop-down techniques and compared the time required. In addition, the authors tried to perform microvascular anastomosis in 15 clinical cases using the drop-down technique. We were able to perform anastomoses quickly using the drop-down, back-wall, and single-knot techniques. The drop-down technique was possible in 12 cases of venous anastomosis in 15 head and neck reconstruction cases. Using this method, we can perform a continuous suture of the posterior wall easily and quickly. The drop-down technique can simplify continuous suturing of posterior wall in the same way as skin suturing.