Fear of childbirth (FOC) is an important women's health issue. The Wijma Delivery Expectancy/Experience Questionnaire (W-DEQ) is currently the most frequently used instrument to measure FOC. The scale is designed to measure different aspects of FOC but is conceptualized as a uni-dimensional instrument. Our aim was to investigate the underlying factor structure of the W-DEQ version A. A total of 1642 women scheduled to give birth at Akershus University Hospital (Norway) during 2009 and 2010 completed the W-DEQ in the third trimester. Validity and reliability were estimated by means of exploratory and confirmatory factor analyses and correlations with other relevant variables. Results confirmed a multidimensional structure of the W-DEQ. Six factors were identified, each measuring different domains: 'Fear', 'Negative appraisal', 'Loneliness', 'Lack of self-efficacy', 'Lack of positive anticipation', and 'Concerns for the child'. The final model resulted in a 25-item version of the instrument with adequate psychometric properties. Subfactors correlated differently with several relevant variables. Especially the factor 'Fear' was highly correlated with both the overall W-DEQ and several important outcomes. Future studies could examine whether this factor may serve as a good proxy for the full W-DEQ version A.