In this paper we prove a general and sharp Asymptotic Theorem for minimal surfaces in H 2 × R. As a consequence, we prove that there is no properly immersed minimal surface whose asymptotic boundary ∞ is a Jordan curve homologous to zero in ∂ ∞ H 2 × R such that ∞ is contained in a slab between two horizontal circles of ∂ ∞ H 2 × R with width equal to π. We construct vertical minimal graphs in H 2 ×R over certain unbounded admissible domains taking certain prescribed finite boundary data and certain prescribed asymptotic boundary data. Our admissible unbounded domains in H 2 × {0} are non necessarily convex and non necessarily bounded by convex arcs; each component of its boundary is properly embedded with zero, one or two points on its asymptotic boundary, satisfying a further geometric condition.