Objective To measure the long‐term impact of surgical treatment for vulval cancer upon health‐related quality of life and pelvic floor outcomes during the first year of therapy. Methods Prospective, longitudinal, mixed‐methods study. Twenty‐three women aged >18 years with a new diagnosis of vulval cancer were recruited. The EORTC QLQ C30, SF‐36 and an electronic pelvic floor assessment questionnaire (ePAQ‐PF) were administered at baseline (pre‐treatment) and 3, 6, 9 and 12 months post‐treatment. Mixed effects repeated measures models (all adjusted for age and BMI) were used to investigate changes over time and differences between cancer stage. Qualitative interviews were carried out with 11 of the women and analysed using a thematic approach. Results Mean age was 59.9 years (SD = 15.3; range = 23.8–86.6 yrs). Mean BMI was 30.0 (SD = 4.5; range = 24.4–38.2). Sixteen women had early (Stage 1 to 2B), and seven women had advanced stage disease (Stage 3 to 4B). Questionnaire scores revealed that physical and social functioning, fatigue, pain and general sex life were significantly worse at 12 months than pre‐treatment (p = < 0.05). Qualitative analysis revealed multiple treatment side effects which were perceived as severe and enduring. Women with advanced vulval cancer had significantly worse SF‐36 mental health scores at 12 months compared to women with early stage disease (p = 0.037). Conclusions Surgery for vulval cancer has long‐term implications which can be persistent 12 months post‐treatment. High rates of morbidity relating to lymphoedema and sexual function re‐enforce the need for specialist clinics to support women who suffer these complications. © 2015 The Authors. Psycho‐Oncology published by John Wiley & Sons Ltd.