Pregnancy and lactation labeling is presented in the officially recognized product information (PI) accompanying prescription drugs to ensure appropriate prescribing in pregnant and breastfeeding women. The aim of this study was to analyze pregnancy and lactation labeling in PI for attention-deficit hyperactivity disorder drugs marketed across countries and to compare this information with respect to consistency and discrepancy. We manually surveyed PI for atomoxetine, methylphenidate, and modafinil marketed by the same pharmaceutical companies in Australia, the USA, Denmark, and the UK. We extracted information regarding data sources (animal and human data), risk to the fetus or breastfed child, excretion in breast milk, and recommendations for use. The extracted information was then analyzed and compared with respect to consistency and discrepancy. Inter-country discrepancies were identified with respect to both animal and human data sources presented, types of risks listed in association with exposure during pregnancy and lactation, information regarding excretion of the drug in breast milk, and recommendations for use. Consistency was identified between PI for drugs marketed in the EU. The study suggests that pregnancy and lactation labeling in PI for drugs marketed by the same pharmaceutical companies depend on the country of marketing; this raises concern about the reliability of PI documents as a useful source of information for appropriate prescribing during pregnancy and lactation. Discrepancies in this information can potentially lead to inappropriate prescribing in pregnant and breastfeeding women, who may expose their fetuses and breastfed children to unnecessary risks. At the same time, unjustified warnings against breastfeeding may result in children being unnecessarily weaned from being breastfed.