Abstract. We give some interest in radial Dunkl processes associated with dihedral systems. We write down the semi group density and as a by-product the generalized Bessel function and the W-invariant generalized Hermite polynomials. Then, a skew product decomposition, involving only independent Bessel processes, is given and the tail distribution of the first hitting time of boundary of the Weyl chamber is computed. 1. A quick reminder We refer the reader to [11] and [16] for facts on root systems and to [5], [20] for facts on radial Dunkl processes. Let R be a reduced root system in a finite euclidean space (V, <,>) with positive system R+ and simple system S. Let W be its reflection group and C be its positive Weyl chamber. The radial Dunkl process X associated with R is a continuous paths Markov process valued in C whose generator acts on C 2 (C)-functions as Lku(x) = 1 ∑ < ∇u(x), α> ∆u(x) + k(α) 2 < x, α> α∈R+ with < ∇u(x), α> = 0 whenever < x, α> = 0, where ∆, ∇ denote the euclidean Laplacian and the gradient respectively and k is a positive multiplicity function, that is, a R+-valued W-invariant function. The semi group density of X with respect to the Lebesgue measure in V is given by (1) p k 1 t (x, y) = cktγ+m/2e−(|x|2 +|y | 2 ()/2t W x√t Dk, y) √ ω