Mammographic screening may reduce breast cancer mortality. Not all women, however, come for examination. The objective in this study from Malmö has been to assess extent to which the rate of nonattendance varies between residential areas with different sociodemographic profiles. The study is based on 32,605 women, 45 to 68 years old and living in 17 areas, who between 1990 and 1994 were invited to screening. Between age groups, the age-specific nonattendance rate ranged from 31% to 35 % (P < .01). The nonattendance rate was highest for women 65 years or older. Between residential areas, age-adjusted nonattendance rates ranged from 23% to 43% (P < .01). A socioeconomic score was developed to express the socioeconomic circumstances in the residential areas and ranged from -7.18 in the most deprived area to 5.01 in the least. Nonattendance covaried in an inverse fashion with the socioeconomic score (r = -0.78; P < .01). One of three women in this urban population did not accept the invitation to mammographic screening. Our conclusion is that women in areas with less favorable circumstances seem to be less willing to participate.