Abstract: Considering a random vector or a random field, we are interested in the estimation of some risk measures of a component of the vector or the field, knowing a subvector. For example, one may have some precise informations on financial products and try to estimate risk measures on another product. We shall focus on elliptic distributions. The main risk measures cosidered will be conditional quantiles and expectiles. This is a joint work with Antoine Usseglio-Carleve and Didier Rullière.