BACKGROUND: Fetal alcohol spectrum disorders (FASD) comprise a continuum of lifelong outcomes in those born prenatally exposed to alcohol. Although studies have shown no differences in rates by race, FASD is of particular concern for American Indian communities. One tribally run prevention program is the Oglala Sioux Tribe (OST) CHOICES Program, which is modeled after the evidence-based CHOICES program that was focused on preconceptional prevention of alcohol-exposed pregnancy (AEP) by reducing risky drinking in women at risk for pregnancy and/or preventing unintended pregnancy. METHODS: The OST CHOICES Program was made culturally appropriate for American Indian women and implemented with 3 communities, 2 on the reservation and 1 off. Data on drinking, sexual activity, and contraception use were collected at baseline and 3 and 6 months postintervention. Data were analyzed using descriptive statistics, 1-way analysis of variance, and a random intercept generalized estimating equation model. RESULTS: A total of 193 nonpregnant American Indian women enrolled in the OST CHOICES Program, and all were at risk for AEP because of binge drinking and being at risk for an unintended pregnancy. Fifty-one percent of participants completed both 3- and 6-month follow-ups. Models showed a significant decrease in AEP risk from baseline at both 3- and 6-month follow-ups, indicating the significant impact of the OST CHOICES intervention. Women in the OST CHOICES Program were more likely to reduce their risk for AEP by utilizing contraception, rather than decreasing binge drinking. CONCLUSIONS: Even with minor changes to make the CHOICES intervention culturally and linguistically appropriate and the potential threats to program validity those changes entail, we found a significant impact in reducing AEP risk. This highlights the capacity for the CHOICES intervention to be implemented in a wide variety of settings and populations.