Does cholesterol screening result in negative labeling effects? Results of the Massachusetts Model Systems for Blood Cholesterol Screening Project. Several previous studies that looked at the effects of labeling individuals as hypertensive found increases in psychosocial distress, diminished feelings of well-being, or absenteeism. Other studies found no such effects. Thus far, similar studies relating to labeling for high blood cholesterol levels have not been published. The Massachusetts Model Systems for Blood Cholesterol Screening Project investigated whether labeling effects occurred as a result of the community-based screening, education, and referral programs it conducted in Worcester and Lowell. Nine questions concerning perceptions of physical and psychological well-being were asked on a questionnaire given to screening participants. The same questions were asked as part of a follow-up questionnaire given to all individuals identified as having high blood cholesterol levels at one of the screenings. Comparison of the baseline and follow-up results did not demonstrate significant overall negative effects among any age, sex, racial, income, or educational groups. On the contrary, responses to many of the questions revealed small but statistically significant improvements in perceptions of physical and psychological well-being. The absence of negative labeling effects may be attributable to the positive, supportive approach to participant counseling taken by the project. 