Purpose: In this study we evaluated the efficiency of diluted triamcinolone particles in peeling of the internal limiting membrane (ILM) in cases of diffuse diabetic macular oedema. Methods: A prospective observational study of thirteen consecutive patients with diffuse diabetic macular oedema who had undergone ILM peeling aided by use of a diluted (1 mg mL-1) suspension of triamcinolone particles (0.05 mg). The results were assessed by measurement of visual acuity and intraocular pressure, by ophthalmoscopy, and by fluorescein angiography. Results: ILM peeling in all eyes could be performed easily and completely with the aid of triamcinolone particles homogeneously dispersed over the macular ILM. During the peeling procedure, triamcinolone particles resulted in clear contrast between the peeled and unpeeled ILM thus enabling us to easily find the edge of the ILM and to be able to continue peeling at further attempts. In twelve of the thirteen eyes the macular oedema was completely resolved or reduced. Visual acuity improved by at least two lines in nine eyes (70%). The intraocular pressure increase did not exceed 21 mmHg in any of the patients. Conclusions: The diluted triamcinolone suspension enables good visualisation of the ILM during the ILM peeling procedure in cases of diffuse diabetic macular oedema. Use of a diluted suspension may reduce the risk of intraocular pressure increase and the potential toxicity of triamcinolone. © Springer Science+Business Media, Inc. 2006.