Purpose: To investigate the diagnostic value of a topical dexamethasone (DXM) provocative test before intravitreal triamcinolone acetonide (IVTA) injection for a steroid response. Methods: Eligible patients scheduled for first-time IVTA without glaucoma or a history of a steroid response received dexamethasone 0.1% drops four times daily over four weeks, whereafter IVTA was given except in DXM responders with an IOP rise >15mmHg. The IOP was measured at baseline, four weeks after DXM treatment, and at weeks 1, 2, and 4, and months 3 and 6 after IVTA. A steroid response after the DXM test or after IVTA was defined as an IOP rise >/=6 mmHg. Results: Thirty-six patients (36 eyes) were analyzed. The DXM test had a sensitivity of 25% (95%CI[0.07,0.52]), a specificity of 100% (95%CI[0.83,1.00]), a positive predictive value of 100% (95%CI[0.40,1.00]) and a negative predictive value of 62% (95%CI[0.44,0.79]) for a steroid response after IVTA. In DXM responders, the IOP rise after IVTA was 17.0+/-7.8mmHg vs. 5.0+/-4.4mmHg in DXM non-responders (P=0.005). The IOP rise after the DXM test correlated with the IOP rise after IVTA (P=0.001). Conclusion: The topical DXM test had a low sensitivity, a high specificity, a high positive and a moderate negative predictive value and may be useful to predict a steroid response following IVTA. DXM responders demonstrated a high IOP rise after IVTA and the IOP rise after the DXM test correlated with the IOP rise after IVTA. If the DXM test is positive, risks and benefits of IVTA should be more carefully weighted.