The objective of this research was to apply the theory of planned behavior (TPB; Ajzen, 1988, 1991) to alcohol use during pregnancy. Of the pregnant women (N = 130) who participated in the study, over one third reported consuming alcohol (34.8%), and the greatest proportion were drinking 2 to 4 times per month (16.4%). Binary logistic regression was conducted, and the full TPB model was able to distinguish between drinkers and abstainers, explaining 57.1% to 77.1% of the variance in drinking behavior. The TPB provides insight into reasons behind the behavior and can be usefully applied, both as a screening tool to identify pregnant women drinking during pregnancy and as an avenue for intervention work.