We present preliminary results on the search for electroweak single top quark production performed by the CDF and DO collaboration at the Fermilab Tevatron collider. Using a dataset of approximately 160pb−1 we find no evidence for a single top quark signal and set 95% C.L. upper limits on the production cross sections: 8.5 pb for the t‐channel and 13.7 pb for the combined t‐ plus s‐channel search.