Assessment of potential developmental and reproductive toxicity of human pharmaceuticals is currently guided by the ICH S5(R2) document. The studies that assess the hazard of both pre- and postnatal exposure are predominantly conducted in rodents (rat and mouse). Utilizing the collective experience of the authors, acceptable designs for both the range-finding and definitive studies are presented with detailed descriptions for the presentation of data. In addition, the suggested initiation and then total duration of these studies in relation to clinical studies are described. Optional parameters that may be included in the studies, as well as possible combination with other study designs are discussed. The details described herein will assist all laboratories performing these studies, individuals who need to plan for the studies, and regulatory agencies that ultimately review these studies.