Prevention of oral chronic graft verusu host disease (GVHD) by topical agents is an attractive strategy because it would potentially avoid the adverse effects associated with systemic immunosuppression. Topically administered dexamethasone solution is a commonly used agent for the prophylaxis of oral inflammatory conditions including GVHD. However, the efficacy and systemic effects of topically administered dexamethasone solution are unknown. We therefore propose this trial designed to evaluate the efficacy and safety of topical dexamethasone solution for prevention of oral chronic oral GVHD in stem cell transplant recipients.