Large randomized clinical trials are becoming more costly, and resources to support them increasingly scarce. Biologic materials, such as blood, DNA, body fluids, or tissue samples collected and stored as a component of these studies represent an invaluable resource, to answer immediate secondary hypotheses, but also as archived material, linked to the study data, for the use of investigators long into the future. The regulatory climate surrounding the storage and future unconstrained utilization of biologic materials is evolving quickly. It is no longer acceptable simply to store samples and use them in an unbridled and unregulated fashion. Thus, to fully utilize the tremendous potential of biologic samples generated from large clinical trials and their related databases, investigators should consider proactively creating a biologic specimen repository, or biorepository. A repository likely assures appropriate subject consent, sample provenance, secure storage, and codified procedures for sample and data retrieval and sharing that protect the subject's confidentiality, the investigator's need for accurate data, and the limited resource. Importantly, the biorepository specimens/samples are typically collected in addition to local and core specimens obtained for the parent study that provide baseline assessments for safety and efficacy outcomes.