This paper considers the mono/multi-periodicity problems in time-delayed memristor-based neural networks (MNNs) possessing impulsive effects, where the input–output activation functions are relaxed to be unbounded and nonmonotonic. Based on differential inclusions theory, several conditions are derived which ensure the existence and multiplicity of periodic positive solutions for impulsive time-delayed MNNs by exploiting Krasnoselskii’s fixed point theorem of multimap type. It should be noted that such periodic positive solutions in MNNs are generated by impulses control. The developed impulses control method generating mono/multi-periodicity of this paper is meaningful for the design and application of time-delayed MNNs circuits in a periodic environment.