BACKGROUND: In primary health care, patient safety failures can arise in service access, doctor-patient relationships, communication between care providers, relational and management continuity, or technical procedures. Through the lens of multimorbidty, and using qualitative ethnographic methods, our study aimed to illuminate safety issues in primary care. METHODS: Data were triangulated from electronic health records (EHRs); observation of primary care consultations; annual interviews with patients, (informal) care providers and GPs. A thematic analysis of observation, interview and field note material sought to describe the patient safety issues encountered and any associated factors or processes. A more detailed longitudinal description of 6 cases was used to contextualise safety issues identified in observation, interviews and EHRs. RESULTS: Twenty-six patients were recruited. Events which could lead to harm were found in all areas of a framework based on published literature. "Under" and "over" consultation as a precursor of safety failures emerged through thematic analysis of observation and interview material. Other findings concerned workload (for doctors and patients) and the limitations of short consultation times. There were differences in health data collected directly from the patients versus that found in EHRs. Examples included reference to a stroke history and diagnoses for CKD and hypertension. Case study analysis revealed specific issues which appeared contextual to safety concerns, mostly around the management of polypharmacy and patient medication adherence. Clinical imperatives appear around risk management, but the study findings point to a potential conflict with patient expectations around investigation, diagnosis and treatment. DISCUSSION: Patient safety work involves further burdens on top of existing workload for both clinicians and patients. In this conceptualisation, safety work seemingly forms part of a negative feedback loop with patient safety itself. A line of argument drawn from the triangulation of findings from different sources, points to a tension between the desirability of a minimally disruptive medicine versus safety risks possibly associated with 'under' or 'over' consultation. Multimorbidity acts as a magnifier of tensions in the delivery of health services and quality care in general practice. More attention should be put on system design than patient or professional behaviour.