The Vud element of the Cabibbo-Kobayashi-Maskawa quark mixing matrix has traditionally been
determined from the analysis of data in nuclear superallowed 0+ -> 0+ transitions, neutron decay, and
pion beta decay. After providing a new test of the conserved vector current hypothesis, we present here a
new independent determination of |Vud| from a set of five
T = 1/2 nuclear mirror transitions. The extracted value, |Vud| = 0.9719 +/- 0.0017, is at 1.2 combined standard deviations from the value obtained from superallowed
0+ -> 0+ transitions and has a precision comparable to the value obtained from neutron decay experiments.