Objective: To summarize evidence regarding current demand for on-demand oral contraception. Study design: We used Medline and collegial contacts to find published and unpublished studies conducted or reported in the past 15 years with information assessing women's interest in using any oral drug preparation, including emergency contraceptive pills, in a coitus-dependent manner either repeatedly or as a primary or planned pregnancy prevention method. Results: We found 19 studies with relevant information. The studies were conducted in 16 countries. Eight studies provided data on women's attitudes regarding a coitus-dependent oral contraceptive; all suggested substantial interest in using it. Nine studies assessed actual use of oral tablets on demand for primary contraception. In these studies, 9-97% of women in the analysis populations reported using the pills on demand as main method, although frequency and consistency of use varied. Reported reasons for interest in or use of this contraceptive approach included convenience, ease of remembering, ability to conceal use, lack of coital interruption, and infrequent sexual activity. Three studies were clinical trials of investigational on-demand oral contraceptives which reported Pearl indices ranging from 6.8 to 53 pregnancies per 100 woman-years. Conclusion: Data from a variety of settings suggest that demand for an on-demand oral contraceptive may be widespread. The effectiveness of this potential method is not established, however. Considering the seriousness of the unmet need for contraception, further development research into the public health benefits and risks of such a method would be worthwhile. (C) 2014 Elsevier Inc. All rights reserved.