Searches for the lightest scalar top quark t-bar_1 and scalar
bottom quark, b-bar_1 performed at LEP2 with a center-of-mass energy of up
to sqrt s = 209 GeV and at Tevatron using data collected at sqrt s = 1.8 TeV
during Run I and at sqrt s = 1.96 TeV during Run II, are discussed.
Different possible decay modes were considered and no evidence for any such
signal was observed. Exclusion limits were extracted.