The purpose of this study was to identify the factors that influence undergraduate college student use of emergency contraception (EC) and their level of knowledge about the product, in order to assist in the development of intervention programmes to increase its use, which could lead to lower rates of unintended pregnancies in this population. A response rate of 98.4% included 1553 surveys from students at 11 Midwestern universities. Students were predominantly female (63.5%), white (75.3%) and aged 18-21 years (80%). They ranged from first-year students (23.8%) through to fourth-year students (13.8%), with second-year students comprising the largest group (32.6%). The majority of respondents reported being heterosexual (92.1%), and 34.1% of those completing the questionnaire reported being in a committed relationship. Most respondents reported having had sexual intercourse at least once in their lifetime (78.9%). Of the 8.4% of sexually active students who had experienced an unintended pregnancy, 18.1% had used EC in the past 12 months. Knowledge of EC was not high; but as knowledge increased, the use of EC increased. The Integrated Behavioural Model predicted 50% of the variance in intention. Each construct contributed a portion of variance except experiential attitude, which was not statistically significant in the path analysis. The model could be used in any future interventions to increase EC use and decrease unintended pregnancies among college students.