Female mice were exposed maternally to clothianidin through diet at levels of 0% (control), 0.002%, 0.006%, and 0.018% during gestation and lactation periods. Selected reproductive and neurobehavioral parameters were measured in F₁ generation. There was no adverse effect of clothianidin on litter size, litter weight, or sex ratio at birth. The average body weight of male and female offspring was increased significantly in a dose-related manner during the lactation period. With respect to behavioral developmental parameters, surface righting at postnatal day 7 of female offspring was accelerated significantly in a dose-related manner (p < 0.05). For movement activity of exploratory behavior at 3 weeks of age, the average speed (cm/s) of male offspring increased significantly in a dose-related manner (p < 0.05). With regard to spontaneous behavior in the F₁ generation, males showed more activity in some measured variables in the middle-dose group. The dose levels of clothianidin in the present study produced several adverse effects in the neurobehavioral parameters in mice.