The response to salty, sour, sweet, and bitter compounds by black-tailed deer (Odocoileus hemiorwus) was determined by use of the two-choice preference test method. Test compounds were sup- plied in water solutions and compared with the consumption of tap water. Chemicals tested were NaCI and Na acetate (salty); HC1, acetic, and butyric acids (sour); saccharin (the non-Na crystalline form), glucose, and sucrose (sweet); and quinine sulfate and quinine monohydrochloride (bitter). Results indi- cated that deer strongly preferred Na acetate solutions ( from 0.04 to 2.S percent) but showed no prefer- ence for NaGl. Deer exhibited a wide range of fairly strong preference for acetic acid (from 0.0067 to 0.16 percent), but not for butyric or HC1 acids. Deer rejected acetic and butyric acids at a much higher pH (3.25 for acetic and 3.95 for butyric) than for HC1 (2.35), which has a less noticeable odor. Deer demonstrated strong preferences for sweet solutions, glucose being preferred over a range from 0.S3 to 20 percent, the highest concentration tested, and sucrose from 0.25 to 10 percent. They also preferred saccharin over a wide range d concentrations (from 0.000625 to 0.160 percent), but to a much lesser degree than for sugars. VVhile no sex differences were observed in responses to sweets, salts, and acids definite sex differences were observed in the response of deer to bitter taste. Bucks demonstrated a marked preference for bitter solutions (from 0.0025 to 0.01 percent for quinine sulfate and from 0.00125 to O.OOS percent for quinine monohydrochloride), whereas the does rejected them at the same concentra- tions.