It has been well recognized internationally that hospitals are not as safe as they should be. In order to redress this situation, health care services around the world have turned their attention to strategically implementing robust patient safety and quality care programmes to identify circumstances that put patients at risk of harm and then acting to prevent or control those risks. Despite the progress that has been made in improving hospital safety in recent years, there is emerging evidence that patients of minority cultural and language backgrounds are disproportionately at risk of experiencing preventable adverse events while in hospital compared with mainstream patient groups. One reason for this is that patient safety programmes have tended to underestimate and understate the critical relationship that exists between culture, language, and the safety and quality of care of patients from minority racial, ethno-cultural, and language backgrounds. This article suggests that the failure to recognize the critical link between culture and language (of both the providers and recipients of health care) and patient safety stands as a 'resident pathogen' within the health care system that, if not addressed, unacceptably exposes patients from minority ethno-cultural and language backgrounds to preventable adverse events in hospital contexts. It is further suggested that in order to ensure that minority as well as majority patient interests in receiving safe and quality care are properly protected, the culture-language-patient-safety link needs to be formally recognized and the vulnerabilities of patients from minority cultural and language backgrounds explicitly identified and actively addressed in patient safety systems and processes.