We have studied the "wrong-sign" process D-0 --> K+ pi(-) to search for D-0
-(D) over bar(0) mixing. The data come from 9.0 fb(-1) of e(+) e(-) collisi
ons at root s approximate to 10 GeV recorded with the CLEO II.V detector. W
e measure the relative rate of the wrong-sign process D-0 --> K+ pi(-) to t
he Cabibbo-favored process (D) over bar(0) --> K+ pi(-) to be R = (0.3321(-
0.065)(+0.063) +/- 0.040)%. We study D-0 --> K+ pi(-) as a function of deca
y time to distinguish direct doubly Cabibbo-suppressed decay from D-0-(D) o
ver bar(0) mixing. The amplitudes that describe D-0-(D) over bar(0) mixing,
x ' and y ', are consistent with zero. At the 95% C.L. and without assumpt
ions concerning charge-parity (CP) violating parameters, we find (1/2)x(/2)
< 0.041% and -5.8% < y ' < 1.0%.