Abstract. Let ψ and ϕ be analytic functions on the unit disk D such that ϕ(D) ⊂ D. We characterize boundedness and compactness of the weighted composition operators f → ψ · (f • ϕ) on BMOA, the space of analytic functions on the unit disk that have bounded mean oscillation on the unit circle, and its subspace VMOA. We also estimate the essential norm of a weighted composition operator on VMOA.