To study sexual activity, the prevalence of sexual dysfunction and related help-seeking behaviors among mature adults in the United States of America, a telephone survey was conducted in 2001-2002. A total of 1491 individuals (742 men/749 women) aged 40-80 years completed the survey. Overall, 79.4% of men and 69.3% of women had engaged in sexual intercourse during the 12 months preceding the interview. Early ejaculation (26.2%) and erectile difficulties (22.5%) were the most common male sexual problems. A lack of sexual interest (33.2%) and lubrication difficulties (21.5%) were the most common female sexual problems. Less than 25% of men and women with a sexual problem had sought help for their sexual problem(s) from a health professional. Many men and women in the United States 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.