Purpose: This retrospective study was undertaken to assess the occurrence of postoperative anterior chamber emulsified silicone oil after intravitreal instillation and to examine the relation between such emulsification and new postoperative glaucoma. Methods: Forty-eight consecutive eyes received intravitreal silicone oil, were followed for at least 1 year, and were evaluated postoperatively by gonioscopy on at least one occasion. Eight eyes received 1000 cs oil, and 40 eyes received 5000 cs oil from which low molecular weight contaminants were removed. All aphakic and pseudophakic eyes received an inferior iridectomy. Oil was removed in 19% of eyes during follow-up. Results: Fifty-six percent of eyes manifested anterior chamber emulsified oil postoperatively. The oil was typically identified only on gonioscopy. This complication developed in 50% of eyes receiving 1000 cs oil and 58% of eyes receiving highly homogeneous 5000 cs oil. Of the 48 eyes, new postoperative glaucoma best explained by interval angle oil emulsification developed in 5 (10%). Conclusion: Anterior chamber oil emulsification occurred frequently, despite inferior peripheral iridectomy in aphakic or pseudophakic eyes and the use of highly purified, higher viscosity oil in 83% of eyes. In this series, new glaucoma in the setting of angle oil emulsification only developed in 10% of eyes. The glaucoma was managed medically in four of five patients.