Many risky actions are carried out under the influence of alcohol. However, the effect of alcoholic intoxication over the willingness to take risks is complex and still remains unclear. We conduct an economic field experiment in a natural, drinking and risk-taking environment to analyze how both actual and self-estimated blood alcohol concentration (BAC) levels influence subjects’ choices over monetary lotteries. Our results reveal a negative impact of both actual and self-estimated BAC levels on risk-taking. However, for male and young subjects, we find a positive relationship between BAC underestimation (a pattern of estimation error which mainly occurs at high BAC levels) and the willingness to choose riskier lotteries. Our findings suggest that a risk compensation mechanism is activated only when individuals’ own intoxication level is consciously self-perceived to be high. We conclude therefore that human propensity to engage in risky activities under the influence of alcohol is not due to an enhanced preference for risky choices. In addition to the suggestion in the existing literature that such propensity is due to a weakened ability to perceive risks, our results indicate that an impaired self-perception of own intoxication level may also be an important factor.