[en] Pb(p,xn) thick target excitation functions were measured in the energy range 10-38 MeV in order to optimize the production of isotopically pure radiobismuth from ^natPb, ²⁰⁶Pb, and ²⁰⁷Pb. Additionally, the decay of Po-isotopes from deuteron irradiation of natural bismuth (²⁰⁹Bi) was exploited for radiobismuth production. ²⁰⁵Bi was produced from ²⁰⁶Pb at 20 MeV with only 2% of ²⁰⁶Bi at 4 weeks post irradiation. Bismuth compounds as used in the treatment of peptic ulcer were labeled with ²⁰⁵Bi for absorption studies in animals and subjects. (Author)