Eighteen eyes with examples of clinically important wound-related complications are reported. These include hemorrhage, fibrous ingrowth, and tractional or mechanical problems. Wound hemorrhages may occur early or late and can be the cause of substantial morbidity. Furthermore, intraocular blood is undesirable because it may provoke cataract formation, contribute to the postvitrectomy fibrin syndrome, induce fibrovascular proliferation, and lead to further surgery to remove the blood. Fibroplasia at the wound sites may in some patients contribute to the development of anterior hyaloid fibrovascular proliferation. Fibrous ingrowth may occur early or late and may be self-limited, with few side effects, or florid, with progression to retinal detachment or phthisis bulbi. Dilation of subconjunctival blood vessels entering the incision site suggests the presence of fibrous ingrowth or fibrovascular proliferation occurring in the vitreous base. Tractional or mechanical problems include retinal breaks, which may or may not lead to retinal detachment, and scarring within the vitreous base, which may contribute to the formation of anterior vitreoretinal traction or anterior proliferative vitreoretinopathy.