The effects of sample preparation and storage on levels of water‐soluble Mn in 5 Mississippi soils were determined. Steam sterilization has the most pronounced effect followed by methyl bromide and various degrees of air‐drying. In general, storage of soils in the moist or frozen condition will result in minimum changes in water‐soluble Mn. However, expected changes are not predictable and each soil will have to be investigated separately if it is necessary to know the effect of a particular treatment on available Mn.