The objective of this study was to examine potential toxic effects which benzodiazepines have on child, if used during pregnancy and breastfeeding. Benzodiazepines are one of the most frequently prescribed drug groups and often used during pregnancy. FDA classified them as ''D'' and ''X'' which brings up many questions pertaining to the safety of their usage in these periods. The literature overview encompassed exclusively a research on clinical cases. Pregnant women are considered to be a sensitive group of patients as their bodies undergo a number of changes that may affect the drug pharmacokinetics. Key factors responsible for the diffusion of a drug through the placenta and its impact on the fetus are following: physical and chemical properties of a drug, the passage rate of a drug and the amount which reaches the fetus, duration of exposure to a drug, characteristics of a drug distribution into fetal tissue, development degree of both fetus and placenta at the time of exposure to a drug, and the effect of drug combinations. Numerous studies indicate that the usage of benzodiazepines during pregnancy is safe; however, a number of cases where the adverse effects were noticed causes doubts and again raises the question of their compatibility with pregnancy. Their usage during breastfeeding is also not recommended because it can affect the baby. Nevertheless, studies show compatibility between benzodiazepines and breastfeeding and that any difficulties can be avoided with a careful choice of drugs; for example, drugs with a short half-life or by limiting the number of CNS depressants used by mother. Of course it is necessary to monitor the child. The use of any drug during pregnancy and breastfeeding is permitted if the benefit for the mother outweighs the risks for the child. Sometimes the untreated condition of the mother can be more dangerous for the child than the exposure to a drug. Knowledge, experience and being up to date with the latest scientific findings will create trust between doctors/pharmacists and patients and provide a happy ending pregnancy and successful development of the child.