It has been suggested that using additional spermicide with condoms provides added contraceptive effect and protection from infection, and that water-based lubricants may lower condom breakage rates. This questionnaire-based study investigated the use of additional lubrication with condoms amongst 525 female students presenting for post-coital contraception, and the current and past experience of condom and additional lubrication use amongst 481 controls attending the same health centre. Of those requesting post-coital contraception, 83% claimed condom failure as the cause, with 66% of the control group having also experienced condom failure at some time. Use of additional water-based lubrication was significantly associated with lower condom failure rates (odds ratio 8.88, 95% C.I.: 3.79, 20.8). Gender, regularity of use of condoms and using oil-based lubricants were not associated with higher failure rates. Additional lubricant use was not significantly associated with increased condom slip-page.