We present recent results of searches forD0−D0mixing, doubly-Cabibbo-suppressed decays, andCPviolation using 9 fb−1ofe+e−collisions collected with the CLEO II.V detector on and just below the&Ugr;(4S)resonance. We have observed the first signal for the “wrong-sign” decayD0→K+&pgr;−&pgr;0.Using theD0→K+&pgr;−final state, we limit the mixing parametersx′andy′to(1/2)x′2<0.041&percent;and−5.8&percent;<y′<1.0&percent;,respectively, and theCPasymmetry inD0→K+&pgr;−to−0.36<AD<0.30at the 95&percent; confidence level. We also measured theCPasymmetry in the decays ofD0to theCP-evenK+K−and&pgr;+&pgr;−final states to be(0.04±2.18(stat)±0.84(sys))&percent;and(1.94±3.22(stat)±0.84(sys))&percent;,respectively. ©2000 American Institute of Physics.