The paper presents the results of laboratory testing of municipal solid waste samples subjected to one-dimensional compression with measurement of lateral stresses. The details of a large-size split-ring apparatus specially developed for this research are presented along with the data on earth pressure at rest and compressibility characteristics. The results show the influence of fibre content on the coefficient of earth pressure at rest in waste materials. The "delayed compression" behaviour observed in the laboratory is shown to be similar to the concepts developed by Bjerrum for normally consolidated sensitive marine clays. Issues such as validity of laboratory testing and sample-size effects are also discussed.Key words: earth pressure at rest, municipal solid waste, compressibility.