This Report provides a conceptual guide for designing statistically based sampling approaches for the analysis of radionuclides in environmental media such as soil, sediment, water, plants, aquatic organisms and animals. Some causes and examples of the magnitude of the observed sampling variability are provided. General concepts and principles of statistical sampling are briefly described in a qualitative manner, including standard sampling designs with their random and systematic errors. This is followed by a presentation of equations and practical examples for estimating statistical quantities such as the means, proportions, or ratios of two quantities. Sampling to estimate spatial patterns, temporal trends, and spatio-temporal variations is briefly described. This Report is also a resource to helpful and relevant statistics literature. It does not attempt to provide step-by-step guidelines for designing specific sampling protocols, nor does it provide details for the analysis of data resulting from sampling programs. For these tasks, advice, recommendations and recipes are found in the literature cited.