OBJECTIVES: For female emergency department (ED) patients, we sought to assess the prevalence of contraceptive usage as well as the extent of contraceptive knowledge and to determine if demographic and sexual health history factors, comprehension of contraceptive methods and moral/religious opinions on contraception were associated with current usage of birth control pills (BCPs), prior usage of emergency contraception (EC) and frequency of condom usage. METHODS: English-speaking female ED patients aged between 18 and 55 years at a northeastern United States urban ED were surveyed on their usage, comprehension and opinions regarding BCPs, EC and condoms. RESULTS: Of the 539 respondents (64.6% were aged </=35 years), most were White (63.1%), single (42.5%), Catholic (48.4%) and privately insured (55.3%). Among the 223 women at pregnancy risk [not currently pregnant, not using any form of nonsurgical birth control (except condoms) and with no prior tubal ligation or hysterectomy], about 25% were using BCPs, fewer than 10% had used EC and almost 40% never used condoms. Most women displayed good knowledge about BCPs and condoms but poor understanding about EC. In multivariate logistic regression analyses, current BCP usage among women at risk of pregnancy was associated with younger age [odds ratio (OR)=0.54; 95% confidence interval (CI)=0.37-0.79], private insurance (OR=2.52; 95% CI=1.30-4.86) and recent intercourse (OR=1.61; 95% CI=1.19-2.18). Among women at risk of pregnancy, those who had an abortion (OR=2.56; 95% CI=1.17-5.61) and those who displayed greater EC knowledge (OR=3.23; 95% CI=1.50-6.95) had greater odds of having used EC. Among all women, more frequent condom usage was associated with being younger (OR=0.57; 95% CI=0.46-0.70), having never been married (OR=0.44; 95% CI=0.28-0.68) and not having intercourse recently (OR=0.79; 95% CI=0.64-0.98). CONCLUSIONS: A high percentage of female ED patients (41.4%) were at risk of pregnancy. Demographic and sexual history factors can help identify women who might benefit from receiving referrals or education on contraceptive measures.