We studied the inhibition of intraocular fibrin formation following infusion of 5 IU/mL of low-molecular-weight heparin sodium (Fragmin, KabiVitrum AB, Stockholm, Sweden) during lensectomy, vitrectomy, and retinotomy in the rabbit model. Surgery was performed on 18 eyes, with nine receiving low-molecular-weight heparin and nine serving as controls. Masked postoperative examinations assessed fibrin quantity, corneal clarity, media clarity, and amount of vitreous hemorrhage. Five (56%) of nine eyes receiving low-molecular-weight heparin did not show fibrin exudation development, with the remainder demonstrating a minimal fibrin response. Eight (89%) of nine control eyes demonstrated prominent fibrin exudation, with five (56%) showing development of a fibrin clot that obscured two or more quadrants of the posterior chamber. No significant difference in the degree of vitreous hemorrhage was noted between groups. Corneal clarity was improved in the heparin-treated group.