Purpose: To evaluate the effect of intravitreal triamcinolone acetonide on serous macular detachment in eyes with diabetic macular edema. Design: Interventional case series. Methods: The study population comprised twenty eyes of 20 patients with diabetic macular edema (12 men, eight,women), aged 48 to 76 years. The eligibility criteria for this study included clinically detectable macular edema in which the presence of serous macular detachment was documented by optical coherence tomography. After intravitreal injection of 0.1 ml (4 mg) triamcinolone acetonide, visual and anatomic responses were observed. 0 Results: In all eyes, after an injection of triamcinolone acetonide, macular edema and serous macular detachment regressed. At 3 and 6 months, macular edema and serous macular detachment had recurred in eight (40%) and nine eyes (45%), respectively. Patients with recurrence were re-treated. No eyes lost vision at 1 month, and all eyes showed improvement. At 3 months, no eyes had lost vision from baseline, and 17 eyes (85%) showed improvement. At 6 months, again no eyes had lost vision from baseline, and 16 eyes (80%) maintained improved visual acuity. Conclusion: Intravitreal triamcinolone acetonide is an effective treatment for serous macular detachment in patients with diabetic macular edema.