We aimed to investigate the association between possible aetiological factors and the risk of developing vulval lichen sclerosus (VLS). A population-based case-control questionnaire study was performed comparing women with a diagnosis of VLS (n= 92), with those attending a general gynaecology clinic with no known anogenital dermatosis (n= 66). After adjustment for confounders, factors associated with VLS included a family history of diabetes mellitus (OR= 7.0, p= 0.012) and previous pelvic surgery (OR= 4.75, p= 0.007). The use of barrier and progesterone only methods of contraception (OR= 0.19, p= 0.045), hormone replacement therapy (OR= 0.209, p= 0.025) or hayfever (OR= 0.18, p= 0.008) appeared to be associated with a reduced risk of VLS. In conclusion, we were unable to confirm many proposed aetiological theories associated with the development of VLS, in particular those associated with autoimmunity.