Key words Hamiltonian elliptic systems, exponential critical growth, Trudinger-Moser inequality MSC (2010) 35A23, 35B33, 35J50, 35J92This paper is concerned with the existence of solutions for a class of Hamiltonian elliptic systems with unbounded, singular or decaying radial potentials and nonlinearities having exponential critical growth. The approach relies on an approximation procedure and a version of the Trudinger-Moser inequality.