In drug development, preclinical development, also termed preclinical studies or nonclinical studies, is a stage of research that begins before clinical trials (testing in humans) and during which important feasibility, iterative testing and drug safety data are collected, typically in laboratory animals.

The main goals of preclinical studies are to determine a starting, safe dose for first-in-human study and assess potential toxicity of the product, which typically include new medical devices, prescription drugs, and diagnostics.

Companies use stylized statistics to illustrate the risks in preclinical research, such as that on average, only one in every 5,000 compounds that enters drug discovery to the stage of preclinical development becomes an approved drug.