Our goal was to evaluate the expression pattern of MMPs and theirs inhibitors during amelogenesis in continuously growing rat incisors. Hemi-mandibles (n=5) were collected from 50 days-old rats. Samples were fixed in 10% buffered formalin, demineralized and embedded in paraffin wax. For immunohistochemistry (sections - 5 µm), we used polyclonal and biotinylated secondary antibodies, the StreptABComplex/HRP kit, and a chromogenic substrate mixture. At the secretory phase, MMPs and Reck were weakly immunostained in the infranuclear region of secretory ameloblasts (SA). MMP9 was also localized in stellate reticulum cells and diffuse Reck staining was found in SA´s cytoplasm. At the transition phase, staining for MMPs and Reck was more prominent in macrophages and/or in dendritics cells of the papillary layer and Reck was also immunopositive in the transition ameloblast. At early and late maturation phases, the profile found for MMPs and Reck was the same as the one found in the transition phase, but the immunostaining was less pronounced. The TIMPs were identified in maturation ameloblasts throughout the maturation phase, but were absent from the other cell types analyzed. We also observed that Reck and MMP9 were immuno-positive in the cytoplasm of odontoblasts, probably at the Golgi apparatus and/or the RER network. Our results suggest: 1) MMP2, 9, and Reck are expressed by non-epithelial immunocompetents cells of the enamel organ; 2) Reck is expressed by ameloblasts and odontoblasts; 3) the MMPs, TIMPs, and Reck are differentially expressed during the different amelogenesis phases in rats, and are likely to play an active role during ECM remodeling.