Background: The way in which patients experience encounters with healthcare professionals seems to affect care outcome, but very little is known about reactions evoked by experiences of negative encounters. Aims: To examine how patients perceive healthcare encounters, with a special focus on negative encounters and feeling wronged. Methods: A questionnaire was sent to 10 042 long-term sickness absentees (response rate 58%). Attributable risk (AR) with 95% confidence intervals (CIs) was calculated regarding relations between experiences of different types of negative encounters with healthcare staff and of feeling wronged. To test the consistency of our results, we also analysed the AR for positive experiences and feeling respected. Results: Of 5802 participants, 1628 reported having experienced negative encounters, and 1036 of them also reported having felt wronged. The types of negative encounters with the highest AR for feeling wronged were ‘nonchalant behaviour’: AR 71.1 (95% CI 66.3–75.8) and ‘treated me with disrespect’: AR 54.8 (95% CI 49.8–59.8). Males in general tended to have higher ARs for feeling wronged than females, as had respondents with psychiatric diagnoses in comparison to other patients. Conclusion: The present study indicates high ARs of feeling wronged among long-term sickness absentees if exposed to negative encounters in healthcare. Nonchalance and disrespect were the most important factors in this regard, but the different types of negative encounters were very much intertwined. Feeling wronged seems to be an outcome based on several experiences of negative encounters, either in a series of events or bundled together in a single event.