T-2 mycotoxin, a natural contaminant of cereals and agricultural products, is known to exhibit the severest toxicity and the lowest LD₅₀ value among trichothecenes. Since quercetin has been reported to have strong antioxidant properties, the effect of quercetin and T-2 toxin on rabbit ovarian cell proliferation and apoptosis was assessed. In the ovaries, proliferating cells were analysed immunocytochemically (proliferating cell nuclear antigen as a marker) and apoptotic cells by the terminal deoxynucleotidyl transferase (TdT)-mediated biotinylated deoxyuridine triphosphates (dUTP) nick endlabeling (TUNEL) method. It was found that: 1. a single dose of T-2 toxin (0.08 mg · kg⁻¹ body weight (BW) 72 h before slaughter) decreased cell proliferation, 2. chronic exposure to quercetin (1 mg · kg⁻¹ BW; 90 days, 3 times per week) results in increased cell proliferation and reduced cell apoptosis, 3. quercetin has the potential to attenuate T-2 toxin-induced proliferation arrest. To clarify the mechanism of T-2 toxin and quercetin action in the rabbit ovary, further experiments are necessary.