The behavioral teratological effects of ethylene-glycol-monoethyl- ether (110805) (EGEE) and ethylene-glycol-monomethyl-ether (109864) (EGME) administered to rats by inhalation were studied. Groups of 15 to 20 pregnant Sprague-Dawley-rats were exposed to 100 parts per million (ppm) of EGEE or 25ppm of EGME on gestation days 7 to 13 or 14 to 20. These concentrations did not cause adverse effects in the dams or mortality or weight reduction in the offspring. Offspring of animals exposed to 100ppm of EGEE on days 7 to 13 of gestation had impaired performance in the open field and rotorod tests and had altered performance in avoidance conditioning when tested between 10 and 90 days postpartum. After exposure to 25ppm of EGME, only the avoidance conditioning test was affected. In newborns and 21 day old animals, neurochemical assays were performed on whole brain, cerebellum, cerebrum, brainstem, and midbrain for acetylcholine, dopamine, norepinephrine, and 5-hydroxytryptamine. Values that were both higher and lower than those of control animals were encountered. Exposure to EGEE during the earlier gestation period resulted in more alterations than later exposure; no such differences were seen with EGME exposure. The authors conclude that their observations draw attention to the sensitivity of the developing organism to the harmful effects of glycol ethers, even at concentrations that produce no adverse effects in maternal animals.