In this paper, an output-feedback control problem is investigated for a class of stochastic systems with impulsive effects under Round-Robin (RR) protocol. First, the RR protocol is exploited for the purpose of effectively relieving communication burden, and energy-saving. The considered stochastic impulsive system is essentially as a switched impulsive one due mainly to the switching feature of the RR protocol. Next, an extended comparison principle (ECP) of the stochastic impulsive systems is developed to handle the effects from both the switching and impulsive signals. By means of this ECP, sufficient conditions are derived to guarantee the exponential mean-square stability of the stochastic switched impulsive system, and then the output-feedback controller is designed through solving a set of semi-definite programming problems. Finally, an example is given to illustrate the effectiveness and applicability of the proposed control scheme.