Litochlebite, Ag(2)PbBi(4)Se(8), is a new selenide mineral from the Zalesi uranium deposit, Rychlebske hory Mountains, northern Moravia, Czech Republic. It occurs as irregular grains up to 200 mu m, which form aggregates up to 1-2 mm in size in a quartz gangue. Litochlebite is opaque, dark grey to black, has a dark grey streak and a metallic luster. No cleavage was observed; the mineral is brittle with an irregular fracture. The VHN(10g) microhardness 230 (227-234) kg/mm2 corresponds to a Mohs hardness of about 3; the calculated density is 7.90 g/cm3. Litochlebite is monoclinic, space group P21/m, with a 13.182(2), b 4.1840(8), c 15.299(2) angstrom, beta 109.11(1)degrees, V 797.3(2) angstrom3, and a: b: c 3.1506: 1: 3.6565. Its average composition (electron-microprobe data) is Cu 0.10, Ag 10.27, Cd 0.05, Pb 11.73, Bi 43.27, Se 32.93, S 0.01, total 98.36 wt.%. The resulting empirical formula, written on the basis 15 apfu, is (Ag1.84Cu0.03)1.87) (Pb1.09Cd0.01)1.10Bi3.99Se8.04. The crystal structure of litochlebite has been solved by direct methods and refined to R(1) = 3.89% on the basis of 938 unique reflections [F(o) > 4 sigma(F(o))] collected on a Bruker AXS diffractometer with a CCD detector and MoK alpha radiation. The crystal structure contains one lead site, four independent Bi sites, four silver sites and eight independent Se sites. One Ag site is an octahedrally coordinated (2 + 4) site in the pseudotetragonal layer, the other Ag site has a distorted tetrahedral coordination. Litochlebite is an Ag-dominant isotype of watkinsonite, Cu2PbBi4Se8, and structurally related to berryite, Cu3Ag2Pb3Bi7S16.