It is now widely established that health care organizations are well advised not only to identify and act upon the concerns of all patient groups but also to encourage and enable them to voice their concerns in the first place. That said, research has begun to reveal that patients differ substantially in their readiness to complain, with many deciding to remain silent even after experiencing severe adverse events. Little research has explored whether patients at the margins (e.g., elderly, disabled, or mentally ill patients) are more likely to remain silent. We examined the extent to which patients' social (being elderly or poorly educated), physical (having a permanent impairment such as deafness, blindness, or a chronic physical condition), and mental marginality (having a mental illness or learning disability) is associated with their intention and perceived ability to complain. We matched survey and patient record data for hospital inpatients treated in the English National Health Service in 2007. We then computed two-stage probit selection models to estimate the cross-sectional association between patients' social, physical, and mental marginality and their intention (Stage 1, N1 = 58,062) and perceived ability to complain (Stage 2, N2 = 3,765). Only 6.47% of all patients intended to complain. Of these, only 10.41% indicated that hospital staff provided them with all the information they needed to complain. An additional 14.70% reported to have received at least some of the information needed for this purpose. Patients above 80 not only exhibited significantly lower intentions to complain than their mid-aged counterparts (-1.16%) but also felt considerably less well informed to file a complaint (-5.45%). Similarly, patients suffering from blindness or a severe vision impairment showed a significantly lower perceived ability to complain (-5.20%). Patients at the margins, especially elderly patients and those with a severe vision impairment, will often remain silent and require special attention, if health care organizations are to listen to-and learn from-the voices of all patients. Our results indicate the need for inclusive complaint procedures designed to fuel organizational learning. Dedicated roles such as case managers and complaint officers might help to make such feedback channels accessible to all patients.