We show that the photoionization dynamics of a small excited polyatomic molecule can be partially elucidated from the measurement of photoelectron angular distributions (PADs) at an energy resolution of only around 20 meV following excitation of various selected rotational levels in an excited electronic state. To illustrate this we present PADs corresponding to the formation of vibrationally resolved NH3+ following the excitation of NH3 to selected rotational levels in its (B) over tilde E-1 " electronic state. We also present a preliminary time-of-flight photoelectron spectrum showing peaks corresponding to resolved rotational levels of the NH3+ ion. (C) 2000 American Institute of Physics. [S0021-9606(00)00422-0].