ABSTRACT The morphology and anatomical structure of the fruits of eight representative taxa, one from each of eight genera of the Oleaceae family (Fontanesia, Forestiera, Forsythia, Fraxinus, Jasminum, Ligustrum, Olea, and Syringa), were investigated. For each taxon, the lateral external appearance of the fruit and transverse sections of the ovary and fruit were examined, and the anatomical structure of the exocarp, mesocarp, and endocarp was described; for genera that did not produce fruits, the structure of the pistil was described instead. Mature fruits were collected as the main material, and for several genera fruits at different developmental stages, as well as flowers and flower buds, were also studied. The pericarp anatomy was examined on light-microscope preparations after fixation in 70% ethanol or storage in Strasburger’s solution, with transverse sections cut on a microtome and the mechanical elements characterized using phloroglucinol and concentrated hydrochloric acid. The results showed that the exocarp is generally a single layer of thin-walled cells covered by a thick cuticle; that the mesocarp is differentiated into an outer zone of thin-walled parenchyma (about 5–15 layers in some genera and up to roughly 30 layers in Olea and Syringa) and an inner zone of two to eight or more layers of isodiametric or elongated, heavily thickened sclereids; and that the endocarp is usually a single flattened cell layer. Parenchymatous strands associated with the dehiscence mechanism, vascular bundles at the outer–inner mesocarp boundary, and calcium oxalate crystals were also observed in particular genera. Comparison of material from in situ and ex situ conditions, and of fresh, herbarium, and carpological specimens, showed that the anatomical structure of the mechanical tissues of the outer fruit layer did not differ, indicating that properly preserved dry fruits can be reliably used for carpological study.