We prove that all Arens extensions of finite rank Riesz multimorphisms taking values in Archimedean spaces coincide and are multimorphisms. also that, for a class Banach lattices F, which includes F=c0,ℓp,c0(ℓp),ℓp(c0), ℓp(ℓs),1<p,s<∞, among many others, Aron-Berner any F-valued multimorphism between