The present paper studies the semantics of the so-called perfective (PFV) form in Arusa (Maasai), using the model of the dynamic (one- and two-dimensional) semantic maps. The analysis demonstrates that PFV is a broad, semi-advanced resultative-path gram. It spans large sections of the two sub-paths of the resultative path: the anterior path (present perfect, perfective and non-perfective past, as well pluperfect and future perfect) and the simultaneous path (present stative). However, the PFV form is incompatible with the input sense of the resultative path (a resultative proper present) and the most advanced stages of the two sub-paths (non-stative present and progressive past). If the information related to prototypicality is included, the map adopts the shape of a wave with the prototypicality peaks located in the area of a perfective past and, to a lesser degree, a present perfect. The senses of a non-perfective past and a stative present are less prototypical. Other senses (pluperfect, future perfect and counterfactual irrealis) are non-prototypical, contributing minimally to the gram’s semantics.