Quantitative findings regarding factors that affect attendance in population-based outreach mammography programmes need to be complemented by descriptive data. The aim of this study was to obtain descriptive insights into the meanings that Swedish women attach to mammograms and their rationales for attending or not attending mammography screening. For this purpose a total of 31 women were recruited to eight focus group discussions. Through inductive analysis, six main themes were identified as important issues in reasoning about attendance or non-attendance in mammography screening: negative experiences, perceived risk factors, knowledge of one's own body, perceived problems with mammography, political, ideological and moral reasoning, and involuntary non-attendance, due to the inability of the screening programme to cover some women (e.g. those with breast implants). In conclusion, there is a need to reinforce the information that mammography is an examination aiming at detecting lumps at an asymptomatic stage. However, the nature and amount of information the women themselves desire is inconsistent. Furthermore, the personal encounter between the individual woman and the staff seems to be of particular importance. An improved dialogue appears an attractive way of adapting the screening situation to meet the varied needs and expectations of the women who are invited.