Results from dust explosion tests carried out with peat dust samples are reported. The maximum explosion pressure and the KSt value have been measured, and especially their dependences on the moisture content and mean particle size have been investigated. It is concluded that the maximum explosion pressure and the KSt value of homogeneous dry (moisture content <35% W/W) and fine (mean particle size <200 μ)_peat dust can be estimated with a reasonable accuracy from the moisture content and the mean particle size. For moist (moisture content >35% W/W) and/or coarse (mean particle size >200 μm) peat dust, it is often possible only to predict whether the dust is explosible or not. For heterogeneous peat mixtures composed of dusts with very different moisture contents and/or mean particle sizes, it is not possible in a reliable way to estimate the maximum explosion pressure or the KSt value based on the mean moisture content and the mean particle size of the mixture. It is not always even possible to predict whether the mixture is explosible or not.