We present the first wood anatomy description for the rare species Dinizia jueirana-facao G. P. Lewis & G. S. Siqueira, which grows in a megadiverse tropical forest subjected to rainfall seasonality, in SE Brazil. Growth rings are visible to the naked eye and demarcated by thin marginal parenchyma bands and, sometimes, by thick-walled fibers in the latewood. Axial paratracheal parenchyma is vasicentric to lozenge aliform with short confluences. Rays are 2-6-seriate, homocellular (procumbent cells) and non-storied. Vessels are visible to the naked eye, some irregular clusters, with diffuse distribution, sometimes filled with gums. Crystals are absent. Intercellular canals of traumatic origin are present. In general, wood anatomical characteristics of D. jueirana-facao agree with those previously reported for other Mimosoid species. As other cooccurring Fabaceae, the studied species has visible growth rings, but more conspicuous than reported for its sister species. Growth rings in D. jueirana-facao are likely triggered by the marked rainfall seasonality.