To study sexual activity, the prevalence of sexual dysfunction and related help-seeking behaviours among mature adults in Spain, a telephone survey was conducted in Spain in 2001-2002. This was completed by 750 men and 750 women aged 40-80 years. Eighty-eight percent of men and 66% of women had engaged in sexual intercourse during the 12 months preceding the interview. Early ejaculation (31%) and lack of sexual interest (17%) were the most common male sexual problems. A lack of sexual interest (36%) and an inability to reach orgasm (28%) were the most common female sexual problems. Approximately 80% of men and women with a sexual problem had not sought help from a health professional. Many men and women in Spain report continued sexual interest and activity into middle age and beyond. Although a number of sexual problems are highly prevalent, few people seek medical help.