A rare Bi-Pb tellurosulfide (the unnamed Pb3Bi4Te4S5) has been found in samples from the Au-bearing quartz-arsenopyrite veins of the Limarinho deposit (northern Portugal), along with other Pb-Bi sulfotellurides, such as aleksite and plumboan ingodite [(Bi0.93Pb0.11)S0.52Te0.42]. This is the first occurrence of these minerals in the Iberian Peninsula. The optical and BSE images of the unnamed Pb3Bi4Te4S5 are the first ever obtained for this mineral. The mineral is anisotropic, pale grey in color, and occurs as tabular grains with perfect cleavage. Electron microprobe compositions of the Limarinho samples confirm the presence of this mineral in nature.