Objectives Patient- centred care is related to better health outcomes, greater patient satisfaction and reduced healthcare costs. One of the core components of patient- centred care, defined in the patient- centred clinical method, is enhancing the patient–doctor relationship. In this study, we aim to measure the therapeutic alliance in consultations between patients and family doctors in Belgium, and explore which patient, provider and practice characteristics are associated with the strength of the therapeutic alliance. Design Cross- sectional cohort study using the Working Alliance Inventory for General Practice (WAI- GP). The patients and family doctors completed a survey after the consultation. The survey consisted of the WAI- GP, demographics, consultation characteristics and variables related to the patient–doctor relationship. Setting Belgian primary care. Participants Every third patient (both practice and house call visits) was invited to participate. 170 patient–doctor dyads from four practices were included. Total of 10 doctors (30% men, age range 24–63 years) and 170 patients (35.9% men, age range 18–92 years). Primary and secondary outcome measures Primary outcome was the WAI- GP score and its correlations with characteristics of the doctor (gender, age) and patients (gender, age, chronic disease, number of annual consultations). results The median WAI- GP score reported after these consultations was 4.5±0.62. Higher WAI- GP scores were reported for consultations with male doctors and by older patients. In the subsample of patients with a chronic illness, higher WAI- GP scores were reported by patients who had more than 10 follow- up consultations per year. Conclusions Consultation quality is an important aspect of healthcare, but attention is needed to understand how the WAI- GP performs in relation to variables that are beyond control, such as gender of the physician, age of the patient and variables related to building continuity of care. This has implications for the measurement of quality of ...