The last decades, an increasing literature on prenatal influences on child behaviour, including temperament, has emerged. This review will give an overview of animal and human studies that have focused specifically on the relation between prenatal stress exposure and offspring behaviour or temperament in early life. The concept and assessment of prenatal stress in animal and human studies is described, and biological responses to stress exposure in humans are discussed. Furthermore, potential mechanisms related to prenatal stress exposure and offspring behaviour are summarized. Findings of both animal and human studies suggest that adaptation to novelty, altered attention, and increased emotionality may be the result of in utero exposure to stress. Although the effect sizes of most studies are rather small, these variations in behaviour could be a risk factor for later psychopathology.