Endocrine disrupting chemicals (EDCs) are environmental contaminants that contribute to rising infertility rates due to their oestrogenic and anti-androgenic activity. Butylparaben (BuP) is one such EDC widely used in Australia as a preservative in person care products, despite being banned in many other countries. The reproductive impacts of butylparaben exposure remain unclear. The aim of this study was to determine the impacts of environmentally relevant butylparaben concentrations on male fertility using a mouse model. From mating, pregnant C57BL6J mice (n=10 per treatment) were administered vehicle control or butylparaben via sub-cutaneous injection at dosages of 0, 2 or 20 µg/kg/day; mimicking the dermal exposure route and equating to average human exposure levels. Dams were sacrificed at e14.5 (n=6 per treatment) or gave birth, with pups continuing to receive treatments until 3 months of age (n>10 males per treatment). BuP exposure had no effect on maternal weight gain, litter size or sex ratios (P>0.1), but exposure to 2 µg/kg/day BuP caused reduced fetal weight (P<0.01). Exposure to 2 µg/kg/day BuP also decreased cholesterol side-chain cleavage enzyme (Cyp11a1) and 17β-Hydroxysteroid dehydrogenase (17-β-hsd-1) expression in the fetal testis (P<0.05), whilst exposure to 20 µg/kg/day BuP decreased oestrogen receptor 1 expression (Esr1) in the fetal testis (P<0.05). In addition, 20 µg/kg/day BuP exposure decreased F1 male bodyweight at 3 months of age (P<0.05). Thus, chronic exposure to butylparaben, at levels equivalent to those experienced by human populations, is sufficient to perturb fetal testicular steroidogenic gene expression, as well as reduce male offspring growth rates. These findings support closer evaluation of the safe levels and use of butylparabens, with further studies required to fully elucidate the long-term consequences on male health and fertility.