Using ionograms from the Brazilian equatorial region of São Luís (SL, 2° S; 44° W, I =-3.8°), the relation between the uplift of the intermediated layers (ILs) at sunset and the prereversal enhancement of the zonal electric field (PRE) is investigated. The ILs were studied during periods of maximum (2003) and minimum solar activity (2009). The presence of the ILs during the PRE occurrence time was very low for both years. In 2003, six ILs’ events were observed, being four of them in the summer solstice and one in the March equinox. In 2009, only a single event was registered and occurred during the December month. The results show that depending on the height at which the ILs are located, their upward movement at sunset can be in some way related to the normal F layer rise at sunset due to the PRE. Additionally, the eastward prompt penetration electric fields (PPEF) during weak magnetic storms can also contribute to the IL’s rise. An interesting case of uplift of a sporadic-E layer from ~120 to 290 km of altitude probably due to the PPEF is investigated. The absence of answers of the F layer to the same disturbed electric field reveals the complex nature of the layers located in the ionosphere valley region.