We evaluated long-term psychosocial consequences of predictive genetic testing, and surveillance behaviour in Lynch syndrome (LS). We conducted a longitudinal study of 208 participants (62 LS mutation carriers and 146 non-carriers) who provided information on general anxiety (State-Trait Anxiety Inventory), fear of cancer and dying, satisfaction with life, risk and test perceptions, and surveillance behaviour in the baseline questionnaire before testing, and 1 month, 1 year and 7 years post-test. At 7 years, most of the psychosocial variables remained unchanged, regardless of mutation status. Carriers tended to underestimate their colorectal cancer risk but were more worried about their cancer risk than their counterparts. Non-carriers reported a higher degree of satisfaction with their testing decisions (P < 0.05), but had more doubts concerning test result validity than carriers (P < 0.05). All carriers attended a post-test colonoscopy surveillance, while 16% of non-carriers reported colonoscopy examinations. Those non-carriers with doubts about test validity were more likely (P = 0.019) to report post-test colonoscopy. Of the carriers, 17% had an interval longer than 3 years between their colonoscopies. Fear of dying soon, measured at 1-month post-test follow-up was the only psychosocial variable predicting non-compliance in recommended surveillance. No adverse psychosocial consequences were detected, and respondents were satisfied with their decision to testing 7 years post-test. Among the carriers, solely fear of dying soon predicted non-compliance in recommended surveillance. Some non-carriers were still worried about their risk and had doubts about the validity of their genetic testing results predicting post-test colonoscopy.