Through careful selection of reduction conditions it is found that both BaPbO 3 and Ba 4 Pb 3 O 10 can be prepared with significant amounts of oxygen deficiency. In both cases, crystallographic unit cells and resistivities change with oxygen content. Hall-effect measurements, however, indicate that the oxygen nonstoichiometry does not change the mobile-carrier concentration, suggesting that the electrons introduced are strongly trapped. The oxygen-deficient materials BaPbO 2.90 and Ba 4 Pb 3 O 9.86 are not superconducting down to 70 mK