Experimentally naive male mice of both strains were exposed to a two-bottle choice situation (ethanol vs. water) and their drinking behavior was observed during the first hour. DBA/2J mice developed a significant avoidance of 2% or 10% ethanol during the first 10 min. At 15 and 60 min following introduction of the bottles, no DBA mouse exhibited more than a 6 mg% blood ethanol level while all of the C57BL mice exceeded this concentration. Significant postabsorptive effects in the DBA mice seem unlikely at these very low blood ethanol values. Animals of both strains were examined for their ability to form lithium-induced conditioned taste aversions to 2% ethanol or 15% sucrose solutions. DBA mice readily formed conditioned aversions to both solutions, but the C57BL strain significantly avoided only the sucrose. C57BL mice appear to have difficulty in discriminating the 2% ethanol from distilled water. The neural sensitivity to ethanol was examined in both strains using the sleep time test and the grid test. C57BL mice were significantly more sensitive than DBA mice in both tests.