Background Use of complementary and alternative medicine (CAM), particularly herbal and alternative medicine supplements, for preconception care and fertility management is becoming increasingly common. Aims To determine the factors associated with the use of CAMs by women for preconception care. Materials and Methods 412 women who had visited an antenatal ‘first visit’ clinic situated at a Brisbane obstetric hospital or had visited a private ultrasound clinic in the same city for the purposes of a routinely indicated ultrasound scan in the first trimester were recruited into the study. Data were collected via a cross‐sectional questionnaire. Results Complementary and alternative medicines (not including multivitamins) were used during preconception by 8.3% of women attending for obstetric care. Approximately half (55.8%) of women taking herbal and alternative medicines ceased these medications on discovery of their pregnancy, though fewer (17.4%) ceased taking multivitamin supplements. Baseline characteristics (age, education and income) are not significantly different between CAM users and those who did not take CAMs preconception. The results of statistical analyses showed that only visiting a practitioner to check for health (OR = 2.00; 95% CI: 1.33, 3.00) and trying to lose weight prior to pregnancy (OR = 1.53; 95% CI: 1.00, 2.36) were the key predictors for women using CAM during preconception. Conclusions Women do consume CAMs to enhance preconception care to a certain extent, though CAM users remain in the minority. CAM users also tend to cease use once pregnant.