A large-scale, nationwide tamoxifen chemoprevention trial is currently being planned as a primary preventive strategy against breast cancer. The recruitment of health asymptomatic women into a long-term clinical trial will pose unique recruitment problems. This study examines the feasibility of telephone recruitment from a health maintenance organization population into such a trial. A random sample of 203 women aged 50 and older with a personal family history of breast cancer were contacted by telephone. A structured interview was administered to assess self-perceived risk of breast cancer, willingness to participate in a trial, and anticipated barriers to participation. Of the 203 names generated from the health maintenance organization membership roster 128 (63%) met eligibility criteria and participated in the interview. Forty-five % of the eligible women expressed interest in the tamoxifen trial. Women who felt that their family would support their participation expressed significantly more interest, while concern about possible side effects emerged as potential barriers. We conclude that contact by telephone among health maintenance organization members can identify a significant proportion of women who are interested in primary chemoprevention for breast cancer. Participation rates may be improved by bolstering family support and by addressing concerns about drug toxicity.