The feasibility of using expanding polyurethane foam as an alternative to sand or water in estimating bulk density by the excavation method was tested. The procedure for using foam was similar to other excavation techniques except that the hole was filled with foam and the resulting hardened case was immersed in water to estimate the volume of the hole. Bulk density estimates for three different soils were determined by the more traditional sand cone and core methods and were compared to estimates derived by the use of the polyurethane foam. No significant differences were found among the three methods for three soils tested. Advantages of using the foam technique are discussed.