Microsurgical reconstruction of the rabbit oviduct was undertaken utilizing either through-and-through sutures including the mucosa, or sutures penetrating the serosa and myosalpinx but not the mucosa. Patency and pregnancy rates did not seem to vary with the suturing technique. However, scanning electron microscopic observation revealed abnormal mucosal fold patterns at 3 weeks after surgery. Fibrinous exudates over the surface of the intraluminal sutures increased with time until the entire surface was thickly veiled by 9 weeks. The observation also revealed regeneration of epithelial cells along the suture. These cells included many abnormal forms such as giant cells and misshapen cells. The majority of these were nonciliated. In theory, the intraluminal suture could form a nidus for epithelial hyperplasia which might cause future tubal obstruction. However, the patency and pregnancy rates obtained with through-and-through suturing were similar to those obtained when the endosalpinx was excluded, both in this study and in previous studies from these laboratories.