Fumonisin B(1) (FB(1)), the most prevalent member of toxins produced by several species of Fusarium molds, which occur mainly in maize, causes several fatal hepatopathies and nephropathies of animals. The current study was scrutinized to ascertain different cytotoxic and morphological transformations in rat hepatocytes induced by the treatments of diverse concentrations (300, 500, or 1000 microM) of fumonisin B(1) in vitro, using both monolayer and spheroid cultures. In each hepatocyte culture, the cytotoxicity of FB(1) was augmented in dose- and time-response manners. Morphological transformations among FB(1)-treated groups integrated accumulation of lipid droplets, cytoplasmic vacuolation in hepatocyte monolayers, and bleb formation in the hepatocyte spheroids. Additionally, electron microscopy revealed the loss of microvilli, mitochondrial swelling, and formation of lamellar membranous whorl in the vacuoles and bile canaliculi-like structures. Appearance of electron dense bodies in the monolayers, and loss of cell-to-cell contact in spheroids were depicted in 1000 microM FB(1)-treated hepatocytes. These outcomes insinuate different vital events in explaining morphological transformations in the cell membrane and organelles, induced by fumonisins in rat hepatocytes.