Introduction: Emergency contraception (EC) reduces women's risk for pregnancy after unprotected intercourse, and women's awareness of the method is increasingly important for expanding access. However, knowledge of EC alone does not predict use, and few population data exist to describe EC use among those aware of the method.

Methods: Using data from the 2003 California Health Interview Survey, we measured EC awareness among 11,392 women ages 15-44, and EC use among 7,178 respondents who were aware of EC and at risk for pregnancy. Using chi(2) analyses and multivariable logistic regression, we examined population characteristics that epidemiologically predict EC awareness and use, including age, race/ethnicity, income, health insurance status, usual source of health care, immigration status, languages spoken at home, and urban versus rural residence.

Results: Nearly 76% of respondents had heard of EC, but awareness was lower among teens, women of color, poor women, women with publicly funded health insurance, those without a usual source of care, immigrants, non-English-language speakers, and rural residents. Among women aware of EC, about 4% reported having used the method in the previous year; young age, low income, attending a community/government clinic for care or not having a source of care, and living in an urban area significantly increased the odds for using EC.

Conclusions: Among California women in 2003, awareness and use of EC remained low. However, similar rates of use were reported among racial, ethnic, and linguistic subgroups. Those most likely to report use of the method included population groups at high risk for unintended pregnancy.