Although mammography has been proven an effective tool in screening asymptomatic women, it has been underused because of poor physician and patient compliance. At a university mammography clinic in Southern California, we administered questionnaires to 381 asymptomatic women to determine what women perceived to be incentives and deterrents to mammography. A factor analysis grouped the incentives into five factors, in decreasing significance: "doctor's recommendation," "personal experience," "media," "others' recommendation," and "breast symptoms." Similarly, we grouped the deterrents according to five factors, in decreasing significance: "cost," "fear of medical intervention," "unnecessary screening," "time demands," and "transportation difficulties." We compared the relative significance of these incentive and deterrent factors for demographics, aspects of the doctor-patient relationship, and individual characteristics. Younger, married women rated incentives, particularly "personal experience," higher and deterrents lower in general than older, unmarried women who had more concerns about "cost." However, all demographic groups rated "doctor's recommendation" as the highest incentive, and we found few differences among races or socioeconomic status for any factor. Women whose physicians had initiated the discussion of mammography viewed the doctor's recommendation as a greater incentive than women who had to initiate the discussion about mammography. Women under the care of gynecologists saw the doctor's recommendation as a greater incentive than women under any other specialists' care. Gynecologists initiated the discussion of mammography and recommended screening more often than other specialists. Women with the following individual characteristics identified more incentives to mammography: knew someone with breast or other cancer, estimated themselves to be at high risk for breast cancer, or had at least one previous mammogram.(ABSTRACT TRUNCATED AT 250 WORDS)