Three nitrile glucosides have been isolated from a methanolic extract of the leaves of Osmaronia cerasiformis (Torr. & Gray) Greene (Rosaceae, Prunoideae). One is the known sutherlandin (Z-4-beta-D-glucopyranosyloxy-3-hydroxymethylbut-2-ene nitrile); the second is Z-4-beta-glucopyranosyloxy-3-methylbut-2-ene nitrile, which has recently been characterized but whose stereochemistry was not previously determined; the Z-isomer identified here was named osmaronin. The third is the new 4-beta-D-glucopyranosyloxy-2R,3R-epoxy-3-methylbutyronitrile (osmaronin epoxide). The nitrile glucosides occur in the leaves and flowers of the title plant; their aglycone is apparently derived from the aliphatic amino acid L-leucine.