INTRODUCTION: Lack of sexual interest is a common sexual difficulty. Estimates of the prevalence of lack of sexual interest vary widely, and the evidence with regard to factors associated with lack of interest is not always consistent. AIMS: The aims of this study were to identify factors associated with reporting lack of interest in sex among women, and to explore whether these factors differ according to whether or not help was sought. METHODS: Our data came from the second National Survey of Sexual Attitudes and Lifestyles, a probability survey of 12,110 men and women aged 16-44 years and resident in Britain between 1999 and 2001 (N = 6,942 women). Computer-assisted personal interviewing was used to collect sociodemographic, behavioral, and attitudinal data. MAIN OUTCOME MEASURES: (i) Persistent lack of interest in sex (>or=6 months or longer in the past year); and (ii) seeking help for persistent lack of interest in sex. We examined data for all women, regardless of their partnership status. RESULTS: In this study, 10.7% of women reported lacking interest in sex for a period of 6 months or longer, and of these, 27.9% sought help for this difficulty. Reporting persistent low desire per se (outcome 1), and reporting seeking help for low desire (outcome 2) were associated with not enjoying sex, wanting sex more often, not being "competent" at first intercourse, poor communication about sex with partner, frequency of sex, and attitudes according sex low priority. Increasing age, reporting a birth in the last year, having children under 5 in the house, and reporting no sexual partner in the past year were associated with outcome 1 only. Being married and self-perceived health status were associated with outcome 2 only. CONCLUSION: Identifying the factors associated with seeking help for low sexual interest is useful in understanding risk markers for problematic sexual interest, and in providing useful avenues for therapeutic discussion.