OBJECTIVE The objective of this study was to determine the prevalence of sexual dysfunction in young women with breast cancer in the Netherlands, and to assess the relationship between sexual dysfunction, treatment methods and treatment-related complaints. Also, the interest among women with breast cancer in receiving care for sexual dysfunction was determined. METHODS Data on sexual functioning were collected through an internet questionnaire. Respondents were included if they had been diagnosed with breast cancer within the past 6 years and were currently 45 years of age or younger. Results were compared with a representative sample of the general Dutch population RESULTS Of the women who were still undergoing treatment, 64 % had a sexual dysfunction. In women who had completed treatment, this was 45 %. All assessed dysfunctions were more common among these young women with breast cancer in comparison with women in the Dutch population. Particularly, early menopause and hormone therapy caused long-term occurence of genital arousal disorder. Radical mastectomy caused long-term occurrence of female orgasmic disorder, and early menopause dyspareunia. Half of the women reported that the topic "changes in sexual functioning" had been brought up during treatment, mostly on the initiative of the health professional. Six out of 10 women with a sexual dysfunction who felt a need for care did not consult a health professional. CONCLUSIONS Sexual dysfunctions are highly prevalent among young women with breast cancer. This appears to improve after treatment has been completed, but women are far from recovered. The initiative to discuss sexuality should lie with the health professional. Including sexuality within treatment guidelines will prevent women with breast cancer from being deprived of care.