The effects of stress (or strain) on the critical current density of "In Situ" multifilamentary superconducting wires are evaluated in high field for axially stressed specimens. The overall critical current density shows no degradation at 14 tesla for stress levels of ∼700MPa for a Cu-36 wt %Nb- 20 wt % Sn material. Preliminary results on the effects of large cyclic stresses are also presented. Prestress models are discussed and compared with the "In Situ" results and previously published experiments.