Purpose <p>As genetic testing becomes increasingly integrated into routine care, understanding its impact on psychological well-being and health-related quality of life (HRQoL) is essential. This study assessed HRQoL, anxiety and cancer worry following hereditary cancer testing in a Swedish clinical setting and identified predictors of these outcomes.</p> Methods <p>Participants were recruited from four outpatient cancer genetics clinics across Sweden. Eligible individuals either carried a pathogenic variant or met clinical criteria for familial breast or colorectal cancer. Questionnaires were completed shortly after receiving test results and again 6 months later. HRQoL was measured using the RAND-36, anxiety using the State-Trait Anxiety Inventory and cancer worry using the Cancer Worry Scale. Outcomes were compared with age- and sex-adjusted Swedish population data. Predictors of outcomes were analysed using multivariable linear regression.</p> Results <p>A total of 254 participants completed at least one questionnaire. HRQoL improved across all domains over 6 months, while anxiety and cancer worry declined. Participants without a recent cancer diagnosis had scores close to population norms at both time points. Those diagnosed within the previous year had lower HRQoL and higher anxiety and cancer worry, although they improved over time. Poorer outcomes were linked to a recent cancer diagnosis, being an index case, female sex and younger age, while education level and the test result itself were not associated with worse results.</p> Conclusion <p>Genetic testing was not associated with substantial short- or medium-term negative effects on HRQoL, anxiety or cancer worry. Individual risk factors should be considered when offering psychosocial support.</p> Plain English summary <p>Genetic testing is becoming more widely used, but earlier research on how testing affects everyday life often involved small groups or older data. Testing is also used in new ways today, which creates a need for updated studies to understand people’s experiences and to see who might need extra support. In this study, we examined quality of life, anxiety and cancer-related worry in people tested for hereditary breast, ovarian or colorectal cancer. They completed questionnaires shortly after receiving their results and again 6 months later. We compared their answers with those from the general Swedish population. Quality of life improved over time, and anxiety and cancer worry decreased. People without a recent cancer diagnosis had scores similar to population norms. Those with a recent diagnosis had lower scores but also improved. Younger people, women and those recently diagnosed with cancer reported more anxiety and worry and lower quality of life scores. Education level and the test result itself did not affect these outcomes. Overall, genetic testing did not appear to cause lasting negative effects. Support may be most helpful for people with these risk factors.</p>