Decahydronaphthalene (DHN), an industrial solvent, was evaluated in OECD TG 421 and TG 443 reproductive toxicity studies in Sprague Dawley rats. In the TG 421, oral doses were 0, 100, 300, or 1000 mg DHN/kg/day. In the TG 443, initial doses of 0, 30, 100, or 300 mg/kg/day were increased to 0, 60, 200, and 600 mg/kg/day on test day 30. High dose TG 421 females exhibited estrous cycle disruption; mid and high dose dams had fewer implantations and pups/litter. High dose F0 females in the TG 443 showed signs of stress: lower body weight, disrupted estrous cycling, higher adrenal and lower thymus weights, adrenocortical hypertrophy and thymic atrophy; these effects were less severe at the mid dose. High and mid dose TG 443 F0 females also had fewer implantations and pups per litter and lower litter weight. F1 females in the TG 443 had nominally fewer F2 pups and lower litter weight. The reproductive effects of DHN indicate impaired ovarian function. Mid and high dose F0 dams in the TG 443 showed clear signs of stress, to which the ovary is known to be sensitive. Therefore, DHN’s effects are considered secondary to maternal stress, and not relevant to humans.