In order to investigate the effect of ethanol on negative priming, 18 subjects aged 18-24 took part in a three-period crossover study in which they received placebo (PL), and two doses of ethanol in random order. The higher dose (E2) produced peak breath alcohol concentrations equivalent to 62.7 mg/100 ml blood, the lower dose (El) 36-4 mg/ 100 ml, Subjects performed a negative priming task in which they detected the larger of two circles which could appear in any of four positions on a monitor. A prime trial was rapidly followed by a probe trial in which either both circles were in previously unoccupied positions (C), or the non-target was in a previously unoccupied position and the target in the same location and the same size as the previous non-target (IR). Negative priming (IR-C) was increased by alcohol, the effect being significant for the lower dose (PL: 13.1 ms; El: 25.2 ms; E 2 21.6 ms). Other performance tasks showed an impairment to divided attention at the higher dose. Subjective drunkenness was significantly increased for both ethanol doses. These results indicate that negative priming is sensitive to the effects of ethanol in doses that do not produce major disruption to performance. These results are in the same direction as those previously noted for drugs acting upon catecholamine systems, and suggest that the specificity of the previous findings may need to be re-evaluated.