To assess contraceptive beliefs and practices among American Muslim women residing in Southern California. English speaking Muslim women were approached in Southern California mosques and online and asked to participate in a survey about birth control. Primary outcome measures included the belief that Islam permitted use of contraceptives to prevent pregnancy, to treat menstrual disorders, and to suppress menstrual flow that would prevent attendance at religious rituals; personal contraceptive use was also assessed. Subgroup analysis investigated potential impacts of demographic variables. The interview response rate was 88%. Among the convenience sample of 276 women, 64.4% were younger than 35 years of age, most were well educated, and had an above average income. Eighty percent of respondents believed that Islam allowed the use of contraception to prevent pregnancy, and 85.1% believed that it allowed for the treatment of menstrual disorders. Overall, 93.4% believed that Islam allowed the use of all contraceptive methods, but 35% believed that Islam did not permit permanent contraceptive methods. Belief was related to higher income or educational level, headscarf use, and being Muslim from birth. Of the reproductive age sexually experienced participants, 96.5% reported ever using any contraceptive method. The most commonly ever-used methods included oral contraceptive pills (72.5%), male condoms (68.9%), coitus interruptus (39.9%), and intrauterine devices (21.2%). The vast majority of American Muslim women surveyed believe that their religion permits use of reversible contraceptive methods. They have used contraceptive methods at rates similar to other women in the United States.